Butterfly knives are illegal in Washington. Under RCW 9.41.250, a balisong qualifies as a “spring blade knife,” which the state classifies as a dangerous weapon. Possessing, manufacturing, selling, or giving one away is a gross misdemeanor, punishable by up to 364 days in jail and a fine of up to $5,000. One caveat matters before you make any decisions based on this: a 2025 bill, SSB 5534, would remove spring blade knives from the banned list, and if it has taken effect the answer flips. Confirm its status before you act.
Why a Balisong Is Banned Under Washington Law
Washington’s statutes never use the words “butterfly knife” or “balisong.” The ban works through a broader category. RCW 9.41.250 prohibits “spring blade knives,” defined as any knife with a blade that opens automatically by a spring mechanism, or that opens, falls, or moves into position by gravity or by an outward, downward, or centrifugal thrust.1Washington State Legislature. RCW 9.41.250 Dangerous Weapons – Penalty A butterfly knife deploys the blade through the centrifugal motion of its two handles, which puts it inside that definition.
The statute does carve out one exception: knives with a spring or detent that creates a bias toward closure, where you have to push the blade open against that bias. That exception covers many assisted-opening pocket knives. It does not cover balisongs, which have no closure bias and open freely with a flick.
What the Ban Actually Covers
RCW 9.41.250 reaches almost every way a person can interact with a butterfly knife. It is illegal to manufacture, sell, give away, or possess one.1Washington State Legislature. RCW 9.41.250 Dangerous Weapons – Penalty Buying a balisong at a shop, ordering one online for delivery to a Washington address, keeping one in a display case, or stashing one in a glove compartment all fall within the ban.
The statute makes no distinction between public and private possession. A butterfly knife locked in a safe inside your home is treated the same as one carried on a city street. Storage is not a defense.
Federal law adds a second layer for anyone bringing a knife across state lines. The federal Switchblade Knife Act (15 U.S.C. §§ 1241–1245) restricts interstate transport of knives with blades that open automatically by hand pressure on a button or by the operation of inertia, gravity, or both. A butterfly knife, which deploys through inertial flipping, arguably fits. Federal penalties run up to $2,000 in fines and five years in prison.2GovInfo. U.S.C. Title 15 Chapter 29 – Federal Switchblade Act Buying a balisong legally in another state and driving it into Washington exposes you to both the federal transport issue and the state possession ban at the same time.
Penalties if You’re Caught
A violation of RCW 9.41.250 is a gross misdemeanor, not a simple misdemeanor. That distinction matters because the two carry very different maximums. Online summaries frequently cite 90 days and a $1,000 fine for butterfly knife possession in Washington. That figure is wrong. Under RCW 9A.20.021, a gross misdemeanor is punishable by up to 364 days in jail, a fine of up to $5,000, or both.3Washington State Legislature. RCW 9A.20.021 Maximum Sentences for Crimes Committed
First-time offenders with no other charges rarely draw the maximum. Judges weigh the circumstances: whether the knife surfaced during a routine traffic stop or during an altercation, your prior record, and how you behaved during the encounter. But the statutory ceiling gives prosecutors leverage, and a gross misdemeanor conviction stays on your record.
Who Is Exempt
Washington law provides narrow exemptions, and they are narrower than internet rumor suggests. General authority law enforcement officers, firefighters, rescue personnel, Washington State Patrol officers, and military members may possess spring blade knives, but only while on official duty, while transporting the knife to or from the place it is stored when off duty, or while storing it. Outside those situations the exemption does not apply.
RCW 9.41.251 adds a separate exception for manufacturers and commercial distributors of spring blade knives. That covers the business side of production and wholesale distribution. It does not help individual owners or collectors.
You may have seen claims online that “licensed performers in the entertainment industry” can legally own butterfly knives for flipping or stage use in Washington. No such exemption exists in RCW 9.41.250 or 9.41.251. A performer in Washington is in the same legal position as any other resident.
The 2025 Bill That Could Change This
During the 2025–26 session, Washington’s legislature introduced SSB 5534, which would remove spring blade knives from the list of prohibited dangerous weapons under RCW 9.41.250. The bill keeps the definition of “spring blade knife” in the statute but explicitly states that a spring blade knife is not a dangerous weapon.4Washington State Legislature. Senate Bill Report SSB 5534 The stated effective date in the bill is July 1, 2025. If it was enacted, possessing a butterfly knife in Washington is no longer a crime.
Whether SSB 5534 was signed into law is not confirmed in the sources this article relies on. Check the Washington State Legislature’s bill tracking page for the current status before you buy, keep, or transport a balisong based on the possibility that the ban has been lifted.
What to Do if You Already Own One
If you have a butterfly knife in Washington today and you do not fall into one of the law enforcement or military exemptions, you are technically in violation of RCW 9.41.250. The safest routes are storing the knife outside Washington, transferring it to someone in a state where possession is legal, or surrendering it. Locking it in a safe at home does not create a legal defense, because the statute bans possession outright rather than carrying.
If you are charged, the exposure is real: a gross misdemeanor on your record, up to 364 days in jail, and a fine that can reach $5,000.3Washington State Legislature. RCW 9A.20.021 Maximum Sentences for Crimes Committed Ignorance of the law is not a defense. If SSB 5534 has taken effect by the time you are reading this, the picture changes entirely. Verifying that first is not optional.