A systematic review and meta-analysis of randomized controlled trials (RCTs) of conventional and biological treatments for moderate to severe psoriasis was conducted. All the trials selected used the Psoriasis Area and Severity Index (PASI) to assess disease severity and used PASI-75 (≥ 75% decrease in PASI score) as the primary outcome. Twenty-four RCTs involving 9384 patients were analyzed; of these, 16 trials were double-blind, placebo-controlled and eligible for meta-analysis. PASI-75 response rates were summarized as risk differences (RDs). Tolerability was assessed from withdrawal and adverse event rates. Infliximab was significantly superior to all other interventions (RD: 77%). Adalimumab (RD: 64%) was superior to etanercept 25 mg or 50 mg twice weekly (RD: 30%, ...