The Roger Willams Park Zoo said 15 cars parked along the main road were broken into Saturday night.
A zoo spokeswoman said the cars were parked between the Natural History Museum and the Botanical Center, and all had their windows smashed in.
One car had a tablet computer visible on the seat.
The spokeswoman said there were no security issues inside the zoo.
The zoo is attracting crowds for the annual Jack-O-Lantern Spectacular.