In ten patients with mild to moderate clinical relapses of ulcerative colitis during treatment with mesalazine (1 g t.i.d.) and with a previous history of poorly tolerated steroid courses, transdermal nicotine (15 mg daily) was added for 4 weeks. Clinical findings were assessed by employing Rachmilewitz's activity index. In 7 of the patients, clinical remission was achieved, the results persisting for up to 3 months after nicotine withdrawal. Endoscopic and histological examination, when performed, confirmed the clinical findings. Nicotine patches may represent a good alternative to steroids in selected patients with mild to moderate relapses of ulcerative colitis. The precise mechanism of action remains unknown.