The shooting occurred about 7:07 a.m. in the 1400 block of South Sacramento, Chicago police said.
Saint Anthony Hospital President Guy A. Medaglia said the shooting happened in Douglass Park, across the street from the hospital.
"Bullets hit the hospital this morning from cars shooting in Douglass Park," Medaglia said in a statement. "Within the last few months shots have been fired outside nearby Sinai and Stroger hospital as well. It is unfortunate that this level of violence in the city continues, affecting so many neighborhoods citywide."
No arrests have been made, police said.
In late September, a paramedic was grazed by a bullet while working on a gunshot victim in the emergency department at Stroger Hospital.
In July, bullets entered the windows of Mount Sinai Hospital after a gunman opened fire outside. No one was injured.
The Sun-Times Media Wire contributed to this report.