We reviewed the mid-term outcome of GSB-III semi-constrained total elbow arthroplasty (TEA) and compared the results of patients with rheumatoid arthritis (RA) and those suffering from post-traumatic arthritis (PTA). Forty-five patients with 54 replaced elbows, with an average age of 69 (range 49-84) were clinically [using Mayo Clinical Performance Index (MCPI) and Liverpool Elbow Score (LES)] and radiographically assessed. The average follow-up was 54 (range 20-103) months. Based on MCPI 82% of patients had excellent or good outcome. This figure was 88% for RA and 64% for PTA group (P = 0.22). Overall MCPI was 83.7(+/- 19) and LES 7.5 (+/- 1.8). Neither the MCPI (P = 0.39) nor the LES (P = 0.95) were statistically different between the RA and PTA groups. The mid-term outcome of GSB-III TEA is satisfactory. The recommendation of TEA, including in patients with PTA, is supported.