Methotrexate (MTX) has become the first-line treatment for rheumatoid (RA) and psoriatic arthritis (PsA); however, few studies have focused on its tolerability. The objective of our analyses was to study RA and PsA patients in whom MTX was discontinued, the reasons for this and the duration of MTX treatment prior to withdrawal. A retrospective electronic database review was undertaken to identify all patients who had received MTX for RA or PsA. Patients who had discontinued MTX were then identified, and the reasons for this were categorised. The duration of MTX treatment was assessed in those who had stopped treatment due to intolerability. A total of 1,257 patients who had received MTX were identified [762 (61 %) RA and 193 (15 %) PsA]. MTX had been stopped in 260 (34 %) patients with RA and 71 (36 %) patients with PsA most commonly due to gastrointestinal intolerability. The median duration of MTX treatment was 10 months in both groups, mean duration 21 and 18.6 months in RA and PsA groups, respectively. Overall, one third of patients with RA and PsA stop MTX most commonly due to poor tolerability. In the context of chronic disease, the median duration of treatment is short (10 months). Our analysis did not include patients who suffer from side effects but continue therapy; thus, the magnitude of the problem may be substantially greater therefore as poor tolerability impacts treatment adherence.