Some antibiotics have been found to modify immune response of the host. Cephalosporins belong to the most frequently used antibiotics. The aim of our study was to evaluate the influence of some cephalosporins on neovascular reaction induced in mice skin by mononuclear cells (MNC) collected from the blood of 12 healthy volunteers. Mononuclear cells or their fractions were injected intradermally into Balb/c mice. Cefradine, cefuroxime, ceftriaxone, cefsulodin, ceftazidime, cefoperazone or PBS (control) were administered subcutaneously into the mice over 3 days at doses of 3, 15 and 75 mg/kg of the body weight. The number of newly formed blood vessels was counted in dissection microscope 72 h after cells injection. Cefradine (each dose), ceftriaxone (75 mg/kg) and cefsulodin (15 and 75 mg/kg) inhibited angiogenic response while cefoperazone did not exert any effect. Cefuroxime (3 and 75 mg/kg) and ceftazidime (15 mg/kg) enhanced neovascular response . Inhibitiory effect of cefradine disappeared after removing monocytes and CD8+ cells from MNC suspension.