It happened before 3 a.m. near the intersection of 61st and Market streets.
Police said they were notified that two gunshot victims had shown up at Penn Presbyterian Hospital.
Officials said both victims are 33 years old and in critical condition and both are in surgery.
One was shot in the abdomen and the other was shot in the leg and hip, according to investigators.
Police say at least one vehicle was hit by gunfire.
Police are also looking for surveillance video.
"We found some projectiles, we found victims blood, we found one vehicle struck by gunfire," said Philadelphia Police Chief Inspector Scott Small. "We did not get any initial calls for gunshots at this location"
It's been a busy night for homicide investigators in the city.
Detectives are also investigating a double homicide in the city's Kensington section where two men were shot and killed late last night.
Police say an 18 and a 26-year-old were killed there Monday night. Both were taken to Temple Hospital where they were pronounced dead.
Police are looking at surveillance video from businesses in that area.
Anyone with information on either incident is asked to contact police.