Notoedric mange, caused by Notoedres cati, affects cats and some rodent species, less commonly dogs and foxes. Young kittens are usually affected. It also causes transient lesions in humans. We report a case of generalized notoedric mange, in an adult tomcat (six years old) consequently to immunosuppression induced by infection with feline immunodeficiency virus (FIV). This is a retrovirus that causes suppression of cellular immunity. The disease manifested as extensive, very itchy crusted dermatitis, deep pyodermatitis on the limbs, and mucopurulent conjunctivitis. The disease is highly contagious. N. cati belongs to the family Sarcoptidae, with a life cycle and morphology very similar to Sarcoptes canis. Diagnosis can be clinically oriented. The distribution of lesions and intensity of pruritus are highly suggestive. Confirmation of mange was made by microscopic examination of the skin scrapings, the parasites being more abundant than in sarcoptic mange. Confirmation of FIV was made with Rapid Antigen FIV Ab/ FeLV Ag Test Kit, Bionote Inc. (Gentaur Group Europe). FIV infection progresses asymptomatically for a long time, being underdiagnosed. Once immunosuppression develops, it predisposes to numerous infectious or parasitic diseases. It is often associated with lymphoplasmacytic stomatitis. Reported dermatological signs include chronic and recurrent bacterial skin infections and otitis, an increased frequency of infection with Cryptococcus neoformans, Candida albicans, or Microsporum canis, and demodicosis.