This review summarizes the clinical importance of six systematic reviews on psoriasis published between January 2007 and October 2008. A meta-analysis demonstrated that several traditional nonbiological systemic therapies have equal or superior efficacy to some biological therapies used in the treatment of psoriasis. Two further meta-analyses comparing biological therapies for psoriasis (excluding adalimumab) have established a hierarchy of efficacy for short-term treatment (10-16 weeks): infliximab > etanercept 50 mg twice weekly > etanercept 25 mg twice weekly > efalizumab > alefacept. Excluding adalimumab, rates of adverse events are significantly higher for biological therapies than for placebo, except for etanercept at both 25 and 50 mg twice weekly. Further, head to head trials of biological therapies for psoriasis and longer-term safety data on their use are required. Psoriasis can be induced by and/or exacerbated during antitumour necrosis factor (TNF) therapy. It is recommended to initially switch anti-TNF agent in this situation and only discontinue therapy if psoriasis is extensive and/or intolerable, allowing the primary disease to remain under control. Most screening and monitoring tests carried out during treatment of psoriasis with biological therapies are neither supported nor refuted by current evidence and the clinician must assess each case individually. Studies designed specifically to assess appropriate use of these tests are required. Further research is needed to evaluate the effectiveness of existing psychological interventions in psoriasis. The effectiveness of support groups has not been adequately proven, although there are limited data supporting the use of cognitive behavioural therapy. © 2009 Blackwell Publishing Ltd.