We estimated the mule deerOdocoileus hemionus peninsulae(Lydekker 1898) population in six locations of an oak-pine forest in the Sierra de La Laguna in the Cape Region of Baja California Sur, Mexico, during 7 consecutive years (1987 to 1993). The most important habitat variables for deer (plant biomass, cover, and water) were measured over five wet and dry seasons at the same locations. The population estimation (based on pellet-group counts) resulted in an average density of 19 ± 5 deer/km2. The deer habitat in the area is typified by different association proportions of Black OakQuercus devia-Pinyon PinePinus lagunae-OakQuercus tuberculata-MadroneArbutus peninsularis.