Background Previous studies of infliximab in psoriasis have demonstrated rapid improvement with induction therapy and sustained response with regularly administered maintenance therapy. Objective The efficacy and safety of continuous (every–8-week) and intermittent (as-needed) maintenance regimens were compared. Methods Patients with moderate-to-severe psoriasis (n = 835) were randomized to induction therapy (weeks 0, 2, and 6) with infliximab 3 mg/kg or 5 mg/kg or placebo. Infliximab-treated patients were randomized again at week 14 to continuous or intermittent maintenance regimens at their induction dose. Results At week 10, 75.5% and 70.3% of patients in the infliximab 5 mg/kg and 3 mg/kg groups, respectively, achieved PASI 75; 45.2% and 37.1% achieved PASI 90 (vs 1.9% [PASI 75] and 0.5% [PASI 90] for placebo; P < .001). Through week 50, PASI responses were better maintained with continuous compared with intermittent therapy within each dose, and with 5 mg/kg compared with 3 mg/kg continuous therapy. Limitations Longer term (>1 year) maintenance therapy and further study of infliximab serum concentrations over this period, in both PASI 75 responders and non-responders, would be preferable. Conclusions Through week 50, response was best maintained with continuous infliximab therapy. Infliximab was generally well-tolerated in most patients. Previous studies of infliximab in psoriasis have demonstrated rapid improvement with induction therapy and sustained response with regularly administered maintenance therapy. The efficacy and safety of continuous (every–8-week) and intermittent (as-needed) maintenance regimens were compared. Patients with moderate-to-severe psoriasis (n = 835) were randomized to induction therapy (weeks 0, 2, and 6) with infliximab 3 mg/kg or 5 mg/kg or placebo. Infliximab-treated patients were randomized again at week 14 to continuous or intermittent maintenance regimens at their induction dose. At week 10, 75.5% and 70.3% of patients in the infliximab 5 mg/kg and 3 mg/kg groups, respectively, achieved PASI 75; 45.2% and 37.1% achieved PASI 90 (vs 1.9% [PASI 75] and 0.5% [PASI 90] for placebo; P < .001). Through week 50, PASI responses were better maintained with continuous compared with intermittent therapy within each dose, and with 5 mg/kg compared with 3 mg/kg continuous therapy. Longer term (>1 year) maintenance therapy and further study of infliximab serum concentrations over this period, in both PASI 75 responders and non-responders, would be preferable. Through week 50, response was best maintained with continuous infliximab therapy. Infliximab was generally well-tolerated in most patients.