Two mountain lions (Puma con-color) were found dead in the Simi Hills area of southern California (Ventura County). Postmortem examination and toxicological analyses indicated that the cause of death was anticoagulant rodenticide intoxication. In addition, both lions had marked alopecia and skin crusts, caused by Notoedres cati. The diagnosis of notoedric mange was confirmed by histology and direct examination of mites obtained from skin scrapings of the two animals. Histologically, the affected skin showed acanthotic epidermis with parakeratosis and parasitic tunnels in the stratum corneum. This is the first report of the pathological changes associated with notoedric mange in free-ranging mountain lions.