Butterfly knives are not illegal in Iowa. You can buy one, keep it at home, and in most cases carry it in public without a permit. The catch is blade length and how you carry: concealing a butterfly knife with a blade longer than five inches is a misdemeanor, and the penalties climb from there.
Iowa’s criminal code never mentions butterfly knives or balisongs by name. Whether yours is legal to carry depends on where the blade falls against the length thresholds in Iowa Code 724.4 and on whether you keep it visible.
Owning One at Home
There is no restriction on owning a butterfly knife in Iowa. Iowa Code 724.4 exempts people who keep a dangerous weapon in their own home, place of business, or on land they own or occupy.1Iowa Legislature. Iowa Code 724.4 – Carrying Weapons That covers a butterfly knife of any blade length on your own property.
The only knife category Iowa flatly bans is the ballistic knife, which has a detachable blade launched by a spring, elastic, or compressed gas.2Justia Law. Iowa Code 724.1 – Offensive Weapons Knowingly possessing one is a class D felony.3Iowa Legislature. Iowa Code 724.3 – Possession of Offensive Weapons A standard butterfly knife, with its blade permanently attached between two handles, is not a ballistic knife and does not fall into that category.
Carrying One in Public
Since July 1, 2021, Iowa has been a permitless-carry state. You do not need a permit to carry a dangerous weapon, openly or concealed, if you are not otherwise prohibited from possessing one.4Iowa Legislature. House File 756 – Enrolled The permit change did not touch Iowa’s separate blade-length limits on concealed knives, and those are what matter for a butterfly knife.
Under Iowa Code 724.4, concealing a knife with a blade longer than five inches but no more than eight inches is a serious misdemeanor. Concealing one with a blade over eight inches is an aggravated misdemeanor.1Iowa Legislature. Iowa Code 724.4 – Carrying Weapons These penalties apply to any concealed knife crossing those lengths, butterfly or otherwise, and nothing illegal has to happen for the charge to stick.
Open carry is treated differently. Iowa has no statewide blade-length limit for a knife carried openly. A butterfly knife worn visibly on your belt, even one with a six-inch blade, does not trigger the concealed-knife penalties. The practical rule: if your blade is over five inches, keep the knife visible.
When a Short-Bladed Knife Still Becomes a “Dangerous Weapon”
Iowa Code 702.7 defines a dangerous weapon in two ways. The first is a list that automatically qualifies certain items, including any knife with a blade longer than five inches. The second is any object used in a way that shows intent to inflict death or serious injury, as long as the object is capable of doing so.5Justia Law. Iowa Code 702.7 – Dangerous Weapon Pulling a short-bladed butterfly knife on someone during an argument can turn a legal pocket knife into a dangerous weapon for that encounter. Blade length controls the automatic rule; conduct controls the rest.
Who Cannot Carry at All
Permitless carry does not help people who are already barred from possessing dangerous weapons under state or federal law, including convicted felons and people subject to protective orders. If you fall into a prohibited category, a butterfly knife that qualifies as a dangerous weapon is off-limits regardless of how you carry it.
Minors
Iowa Code 724.4E makes it a serious misdemeanor for a minor to carry a concealed dangerous weapon.6Iowa Legislature. Iowa Code 724.4E – Possession of Dangerous Weapons and Loaded Firearms by Minors For an adult, a butterfly knife with a blade under five inches is usually outside the dangerous weapon definition. For someone under 18, a prosecutor can argue the knife is designed primarily to inflict injury, which could pull a shorter blade into the statute. Any butterfly knife on a minor should be treated as legally risky.
Places You Cannot Bring One
Even an adult who can lawfully carry a butterfly knife runs into location-based limits.
Government Buildings
Cities, counties, and other political subdivisions can ban dangerous weapons inside buildings they control, but only if they screen entrants and post armed security at the entrances.7Iowa Legislature. Iowa Code 724.28 – Prohibition of Regulation by Political Subdivisions – Exception A county courthouse with a metal detector and an armed deputy at the door can lawfully turn you away. A city hall without screening generally cannot.
Schools and Public Parks
Iowa defines a “weapons free zone” as the area in or within 1,000 feet of a public or private elementary or secondary school, or on public park property. An offense involving a firearm or offensive weapon inside that zone carries a doubled maximum fine.8Iowa Legislature. Iowa Code 724.4A – Weapons Free Zones – Enhanced Penalties The enhancement is written for firearms and offensive weapons, so a standard butterfly knife does not automatically trigger the doubled fine. The underlying concealed-carry rules still apply, and proximity to a school is unlikely to help you with a judge.
Private Property and Workplaces
Private property owners can prohibit weapons on their premises. If a business posts a no-weapons policy or your employer bans knives at work, you have to comply or leave. Iowa does not protect employees who keep weapons in a locked vehicle on an employer’s parking lot, so a knife found in your car can be grounds for discipline or termination.
Penalties
- Concealed knife with a blade over five inches and up to eight inches: serious misdemeanor, up to one year in jail and a fine between $430 and $2,560.9Iowa Legislature. Iowa Code 903.1 – Maximum Sentence for Misdemeanants1Iowa Legislature. Iowa Code 724.4 – Carrying Weapons
- Concealed knife with a blade over eight inches: aggravated misdemeanor, up to two years in prison and a fine between $855 and $8,540.9Iowa Legislature. Iowa Code 903.1 – Maximum Sentence for Misdemeanants
- Using a dangerous weapon during another crime: aggravated misdemeanor, charged on top of the underlying offense.10Iowa Legislature. Iowa Code 724.4 – Carrying Weapons (2026)
- Possessing a ballistic knife or other offensive weapon: class D felony, up to five years in prison and a fine between $750 and $7,500.3Iowa Legislature. Iowa Code 724.3 – Possession of Offensive Weapons
The Forcible-Felony Enhancement
If you use a butterfly knife during a forcible felony, Iowa Code 902.7 imposes a mandatory minimum of five years. The enhancement applies when the trier of fact finds that you displayed a dangerous weapon in a threatening manner, represented that you had one, or were armed with one during the felony. You cannot be paroled until the five years have been served.11Iowa Legislature. Iowa Code 902.7 – Minimum Sentence – Use of a Dangerous Weapon
Buying One Across State Lines
Iowa law controls what happens inside Iowa. Federal law controls what crosses state lines. The Federal Switchblade Act prohibits knowingly transporting a switchblade in interstate commerce, and the federal definition reaches any knife with a blade that opens by inertia or gravity, which covers butterfly knives. Penalties go up to a $2,000 fine, five years in prison, or both.12Office of the Law Revision Counsel. 15 USC 1242 – Introduction, Manufacture for Introduction, Transportation or Distribution in Interstate Commerce
In practice, you can legally buy and carry a butterfly knife within Iowa, but ordering one from an out-of-state seller or carrying one through another state on a road trip creates federal exposure. The federal law does not touch possession or in-state sales. If you’re buying one, an Iowa-based seller is the cleaner path.