Clostridia species are rarely isolated from pleuropulmonary infections in the absence of antecedent trauma. We record the second case reported in the English literature of pneumonia and empyema associated with Clostridium sordelli. This infection is probably acquired through aspiration of oropharyngeal flora and may be associated pulmonary embolism and valvular heart disease. Therapy of empyema associated with C. sordelli should consist of tube thoracostomy as well as penicillin with or without metronidazole or the combination of vancomycin and metronidazole in penicillin-allergic patients.