Psoriasis is a chronic immune-mediated inflammatory disease, with an estimated prevalence of 1-3% worldwide. It is considered to be a multisystemic disorder, primarily affecting the skin and joints (psoriatic arthritis), and associated with other inflammatory conditions such as inflammatory bowel disease and coronary heart disease among others. Today, thanks to recent scientific advances that have allowed us to deepen our understanding of the pathogenesis of psoriasis, we count with an expanded therapeutic armamentarium that includes targeted therapy in the form of "biologics". These agents have gained popularity as safe, effective, and convenient alternatives for the treatment of chronic moderate to severe plaque psoriasis. This review will focus on the main biologics used in the treatment of moderate to severe plaque psoriasis: efalizumab, alefacept, etanercept, infliximab, adalimumab and the new Interleukin (IL) 12/23 inhibitors.