It is well known that the genital skin may be affected by psoriasis. However, little is known about the prevalence and clinical appearance of genital psoriasis, and genital skin is often neglected in the treatment of psoriatic patients. We performed an extensive systematic literature search for evidence-based data on genital psoriasis with respect to epidemiology, aetiology, clinical and histopathological presentation, diagnosis and treatment. Three bibliographical databases (PubMed, EMBASE and the Cochrane Library) were used as data sources. Fifty-nine articles on genital psoriasis were included. The results show that psoriasis frequently affects the genital skin, but that evidence-based data with respect to the efficacy and safety of treatments for genital psoriasis are extremely limited. An advised treatment paradigm for genital psoriasis, based on the levels of evidence, is: first-line: (weak) topical corticosteroids; second-line: vitamin D preparations or tar-based treatments.