Pyomyositis is a pyogenic infection of the skeletal muscles causing myalgia and fever in patients. Hematogenous seeding engendered by persistent bacteremia and septic embolism is usually the underlying cause of the disease. Trauma, intravenous drug use, and immunodeficiency are the main predisposing factors.Obturator internus pyomyositis with sciatica has not previously been reported. We report a rare case of a patient with subacute bacterial endocarditis presenting with left buttock pain and sciatica.Computed tomography confirmed the diagnosis of obturator internus pyomyositis. The patient was discharged uneventfully after successful antibiotic treatment.The mortality rate of patients who have pyomyositis comorbid with another condition or disease is extremely high. Early diagnosis and aggressive management are imperative.