During long-term therapy of hyperuricaemia with allopurinol (300 mg/d) two patients developed generalized granuloma annulare. The diagnoses were confirmed by histology; concomitant diseases, especially diabetes mellitus, were not detectable. Following discontinuation of allopurinol therapy, cutaneous granulomas healed without relapse. Hyperuricaemia could be controlled by low-purine diet and medication avoiding allopurinol. The clinical history of our two patients suggested a causal connection between allopurinol therapy and generalized granuloma annulare. For this reason we rate the development of this disease in both cases as a rare but significant side effect of allopurinol. This should give rise to critical assessment of concomitant drug therapy during development of generalized granuloma annulare.