A 3-yr-old, female captive golden lion tamarin (Leontopithecus rosalia) developed an abscess initially within the oral cavity that progressed to the cheek. Treatment with amoxicillin/clavulanic acid, enrofloxacin, and sulfamethoxizole/trimethoprim resulted in temporary resolution of the abscess. Cultures from the abscess included Escherichia coli, Enterobacter cloacae, hemolytic Staphylococcus, and Serratia marcescens. Histopathology was consistent with chronic cellulitis. Ceftazidime mixed with a thermoreversable polymer gel was surgically placed in the wound to provide long-term local antibiotic therapy. This provided complete resolution of infection without the need for additional surgical procedures.