The Footprints of Life ceremony, organized by Mothers United Through Tragedy, is an annual commemoration of those whose lives were cut short by violence.
Every year since 2001, the group has lined donated shoes - some belonging to murder victims and each pair representing a life lost - on the Art Museum steps.
But this year's ceremony, planned for June 13, may not happen, said Shirley Boggs, the group's founder, whose son was killed 12 years ago.
Most of last year's 333 homicide victims were men, she said, but the count of donated men's shoes has fallen short of that number.
"We need the men's shoes to put on this display of love," she said. "If we don't have an accurate amount, we can't have the program."
After the ceremony, the donated shoes are distributed at the city's homeless shelters.
The group will accept shoes tomorrow from 9 p.m. to 1 p.m. at Broad Street near Girard Avenue, she said.