It happened Saturday afternoon at a food market on Juniper Street.
The victim, who doesn't want to be identified, says the suspect pretended to be a customer, then grabbed her.
She told Action News about the attack through a translator.
"He ran over the cashier and choked her neck and asked her for money," she said.
The owner told her young daughter to go outside and scream for help.
The suspect was caught on another store's surveillance camera. He used a scarf to cover most of his face.
However police say he is described as a African-American or Hispanic man in his late teens, standing about 5'10" inches tall.
Anyone with information is urged to contact Philadelphia Police at 215-686-TIPS (8477), text a tip to PPD TIP (773847) or through PhillyPolice.com.