OBJECTIVES: The introduction of new biologic treatments has therefore dramatically changed the therapeutic management of PsAThe objective of this study was to determine the cost-effectiveness of biologic drugs for patients with moderate to severe psoriatic arthritis (PsA) in Italy. METHODS: ACR and PASI response rates from 8 randomized controlled trials were considered as indicators for clinical efficacy. Short-term efficacy was based on relative probabilities of achieving ACR20 and PASI75 response in a meta-analysis. Published evidence and assumptions were used to predict long-term efficacy. Treatment benefits were determined by the relationship between HAQ and PASI with the EuroQoL 5D. Costs included drug acquisition, administration, monitoring and hospitalisation. ICERs were calculated by ordering treatments by QALYs, and comparing each treatment sequentially. A 40 year time horizon was considered, looking at the Italian perspective. RESULTS: After palliative care, Golimumab was estimated to produce the next most QALYs. However, in comparison to Golimumab, Adalimumab was estimated to provide an additional 0.074 QALYs at less cost and so is a dominating strategy. In comparison to palliative care, Adalimumab had an ICER of € 15,970 per QALY. Etanercept was estimated to give similar additional QALYs and costs to Adalimumab. Infliximab was estimated to provide 0.057 QALYs more than Etanercept, but this came with € 6,938 additional cost, giving Infliximab an ICER of € 121,806 per QALY versus Etanercept. A number of one-way sensitivity analyses were performed finding various parameters (e.g. rate of HAQ progression and baseline demographics) and assumptions (e.g. extent to which HAQ improvement diminishes on withdrawal from therapy) are influential on the ICER. CONCLUSIONS: Our results indicate that Adalimumab, and also Etanercept, have the highest probability of being the most cost-effective of the biologic strategies at typical values of WTP.