He will be back in court Feb 2, when he must show proof of completing the plea.
Along with the 90-day license suspension, Valastro was sentenced to conditional discharge with a $300 fine and a drunk driving program.
The charge is a violation, not a crime.
Valastro says he's "very disappointed" in himself for driving after having a drink in New York City last month. He says he didn't realize he was impaired.
The reality show star said Monday he had only one drink before being pulled over, but he now realizes even one is too many to drive.
According to the New York City Police Department, Valastro, 37, was pulled over in his 2014 yellow Corvette around 1 a.m. on 10th Avenue, and failed a field sobriety test.
Valastro is a bakery owner based in Hoboken with six other locations. He stars in a reality show, "Cake Boss", based on his business that airs on TLC.
According to the assistant district attorney in court, Valastro told officers during the stop, "I had a couple drinks", "You can't arrest me I'm the cake boss!", and insisted to officers several times, "I'm a good guy".
A court complaint said his blood alcohol level was slightly above the legal limit.