The two-vehicle crash happened at about 9 pm. near Highland Park Way SW and West Marginal Way, according to Patrick Michaud with the Seattle Police Department.
Police say the officer was responding to a disturbance call several miles away when he lost control of his car on a wet roadway and spun out, hitting a power pole and the second car.
One officer and four people in the second car were injured in the crash. The officer was trapped inside his car for some time as police and Seattle Fire Department personnel worked to free him.
Rescue crews were eventually able to cut the officer out of his car. He was taken to Harborview Medical Center to treated for what Michaud believes was a shoulder injury.
The woman driving the other car, along with a two 8-year-olds and a 9-year old child were also taken to the hospital, but Michaud does not believe their injuries were serious. A 1-year-old in the car was not hurt and taken home by the father.
Police are still investigating the crash.