The incident happened around 11:20 a.m. at the Burlington Coat Factory in the University Plaza Shopping Center.
Police say the suspect, identified as 20-year-old Darrell J. Coleman, entered the store and immediately started taking his clothes off.
Employees asked him to leave but he disregarded their requests and continued undressing until he was completely naked.
Coleman then began running through the store, police say, and bumped into a female customer who sustained a minor injury as a result.
Officers arrived to find two male store workers in a scuffle with the suspect. It took four troopers to finally subdue the man.
Coleman was transported to Christiana Hospital for evaluation.
One of the male employees was also taken to the hospital for evaluation. The other male worker and the female customer were treated at the scene.
Police say their preliminary investigation indicates Coleman may have been under the influence of PCP.
Coleman faces indecent exposure, resisting arrest and other related charges.
He will be arraigned when he is released from the hospital.