Mycobacterium terrae infection can cause debilitating disease that is relatively resistant to antibiotic therapy. Two cases are presented, and data from an additional 52 reports from the literature are reviewed. Tenosynovitis of the upper extremity, often following trauma, was the most commonly reported presentation (59% of cases), with pulmonary disease occurring in an additional 26% of cases. Underlying medical problems were absent (44%) or not reported (28%) in 72% of the cases. One-half of the patients with upper extremity tenosynovitis were treated with local or systemic corticosteroids, before microbiological identification. Only one-half of the patients with tenosynovitis who were followed up for 6 months had clinical improvement or were cured. The other one-half of the patients required repeated debridement, tendon extirpation, or amputation. The best antimicrobial therapy for M. terrae infection is unknown but might include a macrolide antibiotic plus ethambutol and one other effective drug for at least 12 months after clinical response. Parenteral treatment with an aminoglycoside and surgery may be useful in selected cases.