Hereditary angioedema (HAE) is a life-threatening disorder caused by deficiency or dysfunction of the C1 inhibitor protein. Patients with HAE are restricted in various medical treatments, which can induce an HAE attack. We herein report the first case of psoriatic arthritis (PSA) with type 1 HAE successfully treated with 25 mg of etanercept without HAE attack. Etanercept may represent a useful choice for treating patients with HAE accompanied by intractable PSA and rheumatoid arthritis (RA).