There is increasing use of cytokine inhibitors (including biologics) in the treatment of psoriasis as their efficacy and safety have been demonstrated. Cytokines are important signaling molecules evolved to coordinate a response to infectious threat. In this study, we review available trial, registry and cohort study data pertaining to the immunosuppressive effects of these medications when used to treat psoriasis. The risk of infection associated with these medications is small. Special considerations include the use of these agents in the setting of granulomatous infections, viral hepatitis, human immunodeficiency virus infection, fungal infection and in the perioperative state.