It's part of the effort to end marijuana prohibition around the country.
The interim Seattle Police Chief, Jim Pugel, made it very clear - they're not at the marijuana rally to endorse or condemn marijuana.
They just want to make sure everyting is done legally.
On Saturday afternoon, the marijuana advocates called for changing laws at the federal as well as the state level, something the Obama Administration opposes.
Pugel said the police want to ensure that under the new marijuana law in Washington that only those who are authorized to sell pot will do so and to adults over 21.