We report on 2 patients who developed an acute febrile neutrophilic dermatosis (Sweet's syndrome) and erythema nodosum in association with Crohn's disease. The first patient showed symmetrical painful erythemas on her cheeks after hemicolectomy. Additionally, red painful nodules appeared on her lower legs. The second patient disclosed typical Sweet's syndrome-like lesions with pustules and plaques on her face, scalp and extremities after activation of Crohn's disease. Simultaneously, erythema nodosum-like lesions appeared on her lower legs.