A base jumper has been injured after jumping from a 25-storey building in Perth, police say.

Police believe three men jumped from the top of a building on Adelaide Terrace next to police headquarters, around 2:00am this morning.

One man was taken to Royal Perth Hospital with leg injuries.

Another person fled with the group's equipment before police arrived.

Police are questioning two men and are yet to decide what charges they will face.

Officers suspect the men jumped from the Queens Riverside apartment building.

The injured man is in a stable condition in the hospital's trauma unit.

Police said it was lucky none of the jumpers were seriously injured in the stunt.