We describe a 21-year old man who was diagnosed as having adult onset Still's disease (AOSD) in association with isotretinoin treatment for acne conglobata. The patient was febrile, with a macular salmon pink rash, arthritis, hepatosplenomegaly, and axial lymphadenopathy. Laboratory results showed leukocytosis, mild liver dysfunction and negative rheumatoid factor and antinuclear antibodies. Isotretinoin, an orally active derivative of vitamin A, has been associated with various rheumatologic conditions such as arthralgia, myalgia, vasculitis and arthritis. The etiology of rheumatic disorders associated with retinoids is still obscure; however, it is presumed that immunomodulation by several mechanisms (such as an alteration of the cytokine balance) is probably ascribable to this interesting association.