Grieco, who co-starred on the seminal Fox series as Dennis Booker for 18 episodes between 1988 and 1989, said the new comic take on "21 Jump Street" was surprising.
"I didn't know what to expect," he told ABCNews.com. "They made it into a real funny comedy. There were two ways to go with it, either make it really dark or go overboard and make it funny, and that's what they did. I think they pulled it off in that respect."
Starring Jonah Hill, Channing Tatum, Dave Franco and Ice Cube, "21 Jump Street" is out in theaters now. Check out Grieco hamming it up at the Los Angeles premiere below.