The Police Athletic League held the event at its center in Harlem on Saturday.
The party included an inflatable obstacle course, carnival booths and face painting.
Police Commissioner Ray Kelly was also on hand.
He says he was involved in the P.A.L. when he was a boy.
"It's important for young people to be aware of the police department. To see that we support the P.A.L., that there are activities here that can help them grow," Kelly said.
The P.A.L. provides educational and social activities for more than 50,000 boys and girls every year.