Sodium fusidate ointment and mupirocin ointment were compared in 354 patients with superficial skin sepsis. The ointments were applied 3-times daily, or once daily when covered by a dressing, and the response assessed after 6 to 8 days. Both preparations proved effective clinically with 86% of patients responding. There was no difference between the two preparations in cases of primary infection (85% to both ointments), including a sub-group with impetigo (sodium fusidate 88% and mupirocin 84%), or secondary infection (sodium fusidate 81% and mupirocin 89%). Sodium fusidate ointment (98%) was significantly better (p less than 0.05) than mupirocin (82%) in patients with other superficial infections. Both ointments were equally effective in cases where Gram-positive, Gram-negative or mixed Gram-positive/Gram-negative bacteria were isolated. Adverse effects were reported in 1.0% of patients using sodium fusidate ointment and in 7.4% of patients using mupirocin ointment. The majority of complaints concerned the greasiness of mupirocin ointment.