Police were called to Liberty Park at about 8:30 p.m. after getting calls about a gun battle near the park's tennis courts and a skateboard park.
When they arrived, they found a 20-year-old woman with two gunshot wounds to the torso.
Medics rushed the woman to the hospital. The woman's condition is unknown, but police say she was "seriously wounded." No one else was injured in the shooting.
"At this point we have several witnesses we're interviewing. We're really not sure what we have, but hopefully we'll find out more information soon," said David Leibman with the Renton Police Department.
Witnesses at the park say the the shooting started with an argument between several men.
"One of the guys went to break them up or something and he hit one of them, then pulled out a gun. Then another dude pulled out a gun and they both started firing at each other. It was pretty intense," a witness said.
Police have not made any arrests and do not have any suspects in the case. Detectives remained at the scene to investigate.