Sweet's syndrome is rare acute febrile neutrophilic dermatosis whose onset is either idiopathic or associated with other underlying conditions, such as infections, autoimmune diseases, pregnancy, use of certain medications, or malignancy. We report the case of a young male with known history of ulcerative colitis and abrupt onset of high fever, malaise, blurred vision and eruption of painful erythematous nodules and papules, localized on the head, neck, trunk and upper limbs. Ophthalmological examination established the diagnosis of anterior uveitis. Inflammatory markers were positive. Histological examination of skin lesions revealed a dense neutrophilic infiltrate of the dermis. Clinical, laboratory and histological findings were suggestive for the diagnosis of Sweet's syndrome and uveitis on a background of ulcerative colitis. Systemic and ophthalmic administration of corticotherapy leads to a prompt resolution of symptoms and inflammatory syndrome. The particularity of this case is the occurrence of two simultaneous extraintestinal manifestations in a young male with inflammatory bowel disease and colonic involvement. Although a relatively rare condition, Sweet's syndrome should be considered as a differential diagnosis in patients with acute onset of high fever and skin rash, as it may have notable internal involvement and can be easily treated.