Police in Winter Garden, Florida say a robber demanded cash, telling two clerks to open the station's safe, early Monday.
The robber then fired at the clerks.
The clerk didn't realize he'd been shot until police arrived.
"The clerk said I feel like my chest hurts and they started looking at the clerk as the guy had actually shot at him, hit him, struck his cellphone, and the cellphone had stopped his bullet," Winter Garden Police Department Lt. Scott Allen said.
Police say the pain was caused by the blunt trauma of the bullet striking the phone, which the man had in his shirt pocket. Doctors looked at the clerk and he had no other injuries.
Police are still looking for that robber.