Pyomyositis, a suppurative infection of the skeletal muscle, is uncommon and frequently misdiagnosed. Staphylococcus aureus has been reported as the most common causative organism in the tropics. The purposes of this study were to examine the clinical courses including presentations, treatments, and final outcomes of Staphylococcal pymyositis in Chang Gung Memorial Hospital and to suggest a treatment modality for this disorder. From July 1985 to June 1994, 12 patients were treated in this hospital for Staphylococcal pyomyositis. There were 9 males and 3 females, whose mean age was 22.1 years. The involved patients were either in the first two or in the fifth to seventh decades of life. Fever was found in all of them. The average time lag in diagnosis was 11.8 days from the onset of minor symptoms. The Gallium-67 scan was very sensitive and valuable in localization of the disease. Debridement or surgical drainage of the abscess was done in 11 patients. All the patients recovered after between 4 and 6 weeks of adequate antibiotic treatment without major abnormalities and complications. In summary, Staphylococcal pyomyositis is a rather benign disease. However, diagnosis is often delayed due to its vague presentation and lack of clinical suspicion. Unfamiliarity with this disease may be an obstacle to appropriate management.