The jumpers face trespassing charges, according to a report provided by Public Affairs Officer Brian Pritchard.
The BASE jumpers purchased tickets and entered the Space Needle at about 8:50 p.m. Friday, according to the Seattle Police Department. The popular attraction has a round observation deck surrounded by high glass windows that are open to the sky above.
They were seen on camera at the top level of the Needle then went into a restroom, coming out with helmets on, according to police.
They ran to the glass window, climbed over to the other side, and jumped off, according to police.
Security at the Space Needle were unsure where the men landed, and police could not locate the individuals. They have not been identified by authorities and were described only as white men in their late 20s.
BASE jumping is an extreme sport that involves jumping off objects and deploying a parachute. It is an acronym for the platforms parachutists leap from: buildings, antennas, spans (bridges) and Earth.
The Space Needle did not immediately return emailed requests for comment on Saturday.