Introduction Monoarticular presentation of rheumatoid arthritis is infrequent and it usually occurs in the hip and knee joints. We report such a case in a 70-year-old male with monoarticular rheumatoid arthritis of the left wrist. Case report A 70-year-old male patient presented with pain and restriction of movements of his left wrist. Radiographs showed lytic lesions in distal radius and carpal bones, concentric reduction of wrist joint space and periarticular osteoporosis. Erythrocyte sedimentation rate and C-reactive protein were elevated. Rheumatoid factor was negative. Uric acid levels were normal. Joint aspirate culture was negative. Anti-citrullinated cyclic peptide was strongly positive. Following treatment using diseasemodifying anti-rheumatic drugs, patient improved signi icantly. Conclusion Our case did not have the classical features of rheumatoid arthritis. Monoarticular presentation of rheumatoid arthritis is rare, of which isolated wrist involvement is even rarer. Rheumatoid arthritis should be considered in the differential diagnoses of monoarticular arthritis, and anticitrullinated cyclic peptide should be used more frequently to diagnose rheumatoid arthritis in doubtful cases.