OBJECTIVES: The main aims of this systematic review were to identify all relevant literature on clinical efficacy for biological medications in patients with psoriasis and to conduct an up-to-date meta-analysis. METHODS: The following comparators were considered for this analysis: adalimumab, etanercept, infliximab, and ustekinumab. A MEDLINE search was conducted until March 2013. The Cochrane Highly Sensitive Search Strategy was applied to identify randomized controlled publications and was combined with ‘psoriasis’ MeSH terms and drug names. Randomized, controlled, clinical trials with adults with moderate-to-severe psoriasis where the full paper can be obtained were included. Evidences were combined in a mixed treatment comparisons in a Bayesian framework. Efficacy was measured by the 75% and 90% improvement of Psoriasis Area Severity Index (PASI) at three months were analysed. RESULTS: Nineteen trials were included in this indirect comparison; treatment arms with off-label dosages were excluded. Each biologic showed significantly more favourable effect than placebo with respect to any level of PASI response. Significantly more patients on infliximab treatment met PASI75 endpoint than on etanercept, adalimumab or ustekinumab, combined odds ratios (95% confidence intervals) were 5.34 (2.29-12.50), 7.49 (3.31-16.92) and 3.64 (1.62-8.20) respectively. Similarly, significantly more patients on infliximab treatment met PASI90 endpoint than on adalimumab or etanercept, odds ratios were 6.12 (1.07-34.86) and 7.78 (1.02-59.01). No significant differences in terms of PASI75 and PASI90 improvements were observed between adalimumab, etanercept or ustekinumab. CONCLUSIONS: All biologics demonstrated statistically significant improvements compared to placebo. This review also showed that infliximab was significantly more efficacious than other biologics.