Currently there is no curative treatment for psoriasis. Traditional therapies aim first of all to suppress the symptoms. New systemic biological agents – recombinant proteins designed to block specific steps of immune activation – have been shown to be effective in psoriasis. By now five biologicals have entered at least phase III clinical trials for psoriasis: alefacept, efalizumab, etanercept, infliximab and adalimumab. Their selectivity, clinical efficiency and relative safety offer an alternative for treating moderate to severe psoriasis. This review reports the current knowledge of biologicals for psoriasis in clinical use.