In the present study the antiinflammatory activity of fusidic acid was investigated in a model of formalin-induced edema formation in rats. Fusidic acid at doses of 50 and 100 mg kg-1 was administered p.o. to rats for ten days. It was observed that fusidic acid inhibited edema formation significantly (P < 0.05). After this period, gastric mucus secretions were evaluated by the Alcian blue dye binding method. Mucus secretion decreased significantly in the control group. Fusidic acid increased the amount of gastric mucus. Moreover, in all of the animals with paw edema, platelet count was also increased. Red blood cell count, haemoglobin concentration and haematocrit were all higher in the control group than those of the fusidic acid groups. The present observations suggest that fusidic acid suppressed the inflammatory response and stimulated the gastric mucus secretion and it prompts further experiments for delineation of the mechanism of these actions as well as clinical trials. © 2002 Published by Elsevier Science Ltd.