Anti-TNF agents are widely used in the treatment of some inflammatory diseases, such as inflammatory bowel disease and psoriasis. Their use has led to a significant advance in the treatment of these diseases. Paradoxically, the onset of psoriatic lesions has been observed in patients on anti-TNF treatment. The cause of this side effect has not yet been clearly identified. In recent years, an increasing number of cases of psoriasis related to anti-TNF therapy in inflammatory bowel disease patients have been reported. Although withdrawal of anti-TNF was usually implemented in the first reports, in more recent series the maintenance of the drug with topical therapy, with the exception of the most severe or extensive forms of skin lesions, appears to be the treatment of choice. This article summarizes the relevant literature, discusses the etiopathology, epidemiology, location and phenotypes of psoriatic lesions and the management of this side effect.