The incident happened Wednesday night at a CTA station near Wrigley Field.
Police spokesman Wayne Frisbie says two men were smoking, and three officers asked them to put the cigarettes out. Frisbie says one of the men complied, but the second one started a fight. As police tried to restrain him, a third man jumped into the fray.
A fourth officer arrived to help subdue and arrest the attackers.
The melee left one officer with severe injuries to his face and the three others with minor bruises and cuts.
Police say charges are being considered in the case.