The attack happened early Saturday in the 1700 block of Warwick Avenue.
According to police, the female victim said she was out walking her dog when two men grabbed her and dragged her behind a bush.
She said one man held her while the other, wielding a knife, removed her clothing and sexually assaulted her.
The two men then fled, apparently scared off by an approaching vehicle.
The woman was able to describe the man she said raped her.
Police released a composite sketch of an African-American man, about 6 feet tall, with short hair and no beard or mustache.
They are asking anyone who recognizes the man in the sketch, or has information about the attack, to call 911, Folcroft Police Corporal Christopher Eiserman, or Folcroft Police Corporal William Bair at 610-522-1300.
