Arthrodesis of the thumb metacarpophalangeal (MP) joint exhibits good results in rheumatoid patients but is controversial in post-traumatic conditions. This study evaluated the subjective outcome after thumb MP joint arthrodesis in chronic injuries and non-rheumatoid degenerative disorders. Forty-six patients were evaluated retrospectively with a mean follow-up of 4.1 years (range 1.5-6.5). Both the Quick DASH score (mean 18.6; range 0-72.7) and Visual Analogue Scales (satisfaction, pain, stiffness, and impairment of ADL; mean 3.2, 3.0, 3.0, and 2.5; range 0-9.6, 0-9.1, 0-9.8, and 0-9.6, respectively) showed wide variations. Twelve patients regretted the operation and 37 experienced difficulties with one or more specific activities. Multiple regression analyses indicated that elderly patients with painless instability are the best candidates for thumb MP joint arthrodesis. In young patients with excessively painful thumb MP joints and involvement in Workers' Compensation Board claims, but without advanced degenerative changes, this study recommends avoiding arthrodesis and considering alternative treatment modalities. The importance of adequate preoperative information about the realistic expectations after arthrodesis of the thumb MP joint is emphasised.