Officials say someone got in through the front door of the store around 9 p.m. Thursday. The store is located on N. 8th St.
Officers got to the scene two minutes after an alarm went off.
Police say several glass jewelry cases were smashed and jewelry from the cases was taken.
Police aren't sure how many people are involved.
It's not known how much jewelry was taken.
If you have information, call the Sheboygan Police Department at (920) 459-3333.