Tumour necrosis factor (TNF)-alpha plays an important role in the pathogenesis of psoriasis. Infliximab is an anti-TNF-alpha chimeric monoclonal antibody, which is licensed for the treatment of rheumatoid arthritis and Crohn's disease. Some reports have shown the efficacy of infliximab, either in monotherapy or in combination with methotrexate, for the treatment of psoriatic arthropathy and psoriasis. The efficacy and tolerability of infliximab monotherapy was evaluated in 29 patients with moderate to severe psoriasis, unresponsive to conventional treatments. Fourteen patients suffered from concomitant arthropathy. Patients received intravenous infliximab, 5mg/kg, at weeks 0, 2, and 6. After this 3-dose-induction regimen, patients were followed-up at monthly intervals and retreated with a single-dose infusion in case of relapse of signs and symptoms. Clinical assessment was performed using the psoriasis area and severity index (PASI) to monitor psoriasis activity; pruritus and joint pain were assessed on a scale of 0 to 3. A marked improvement of skin lesions and subjective symptoms was noted in the majority of patients; an excellent reduction of PASI score (> or =75%) was observed in 13.8% of cases at week 2, 71.4% at week 6 and 78.6% at week 10. During the follow-up period, some patients maintained satisfactory clinical results without requiring any additional infusions. In general, skin lesions showed a trend towards a more prolonged and sustained improvement as compared with subjective symptoms. Treatment was well tolerated and no serious adverse events occurred.