Nocardia commonly is thought of as producing a chronic pulmonary or granulomatous skin infection, but this report illustrates that it may begin as an acute inflammatory process. In view of the tenosynovitis which followed exploration of the tendon sheath in the patient presented and which required a second operation, it may be better to aspirate the sheath at a distant site to look for pus. Actinomycetes should be suspected and looked for with appropriate methods in any suppurative lesion, especially one not responding to conventional antibiotics.