Police spokesman Hubert Henderson says the officer, James Kniepp, was flagged down as he drove past the restaurant.
Kniepp successfully delivered a baby boy, born two months pre-mature, in the bathroom.
Kniepp, who has been with the department 24 years, tells the Star-Ledger of Newark that he pulled from his EMT experience at the police academy.
The baby and mother were taken to Beth Israel Medical Center and are reported to be in good health.
