Pyogranulomatous pneumonia was detected in two koalas (Phascolarctos cinereus). Nocardia asteroides was isolated from one koala with extensive pneumonia, pleurisy and splenitis. Staphylococcus epidermidis was isolated from a second koala with pneumonia restricted to the left cranial lobe. Both koalas were in poor condition and had underlying urogenital disease. It was concluded that each organism had acted as an opportunistic pathogen in its compromised host.