This is a report of a twelve-year-old black male who presents a history of left neck pain, left shoulder pain, weight loss and minimal fever. The admission diagnosis was a malignancy, supported by radiographic findings of consolidation of left lower and left upper lobes and periosteal new bone formation along the inferior aspects of the left second, third and fourth ribs. Open biopsy of the chest wall revealed a large abscess cavity. Subsequent cultures on anaerobic blood agar plates grew Actinomyces and Fusobacterium. The patient was treated with penicillin and improved clinically. This case emphasizes the need to culture tissue specimens for a wide array of organisms, including those not commonly seen today. A high index of suspicion is required for the diagnosis of anaerobic infections. Mixed anaerobic infections, including actinomyces, although uncommon in children, should be considered in the etiology of an intrathoracic mass.