A markedly obese 54 year old woman with seropositive rheumatoid arthritis, anaemia, dyspepsia, controlled hypothyroidism and depression presented with a seven month history of large pyoderma gangrenosum ulcers on the shins. Routine dressings for the ulcers had been ineffective. Her arthritis was being treated with azathioprine and NSAID's. Initial treatment with clobestasol propionate and disodium cromoglycate under occlusion produced only partial healing. Introduction of Cyclosporin A and continuation of topical therapy, with the addition of triamcinolone acetonide injections, led to progressive healing which was complete after seven months. There has been no relapse to date. Cyclosporine can be combined with azathioprine and local therapy for successful treatment of pyoderma gangrenosum.