Pustular psoriasis is an uncommon variant of psoriasis characterized by widespread pustules on an erythematous background. Recent reports document the efficacy of immunobiologic agents such as infliximab in the treatment of pustular psoriasis. We present a patient that developed cutaneous and pathologic changes consistent with pustular psoriasis while receiving treatment with infliximab for chronic ulcerative colitis. More long-term studies need to be conducted in order to fully understand this paradoxical reaction as well as the mechanism of action and side effect profiles of infliximab and other immunobiologic agents.