Ariocarpus bravoanus grows on gravelly flat and slightly sloping terrain among calcareous rocks in xerophytic shrubland. The habitat is locally classified as matorral desértico micrófilo. One location is very near a village, and there is a serious threat of habitat alteration. The site is also well-known to both commercial and amateur collectors and there is definite evidence of illegal collecting. The other sites are far from villages or other human activities, so there is less likelihood that they will be affected by habitat alteration. Local people also use several ariocarpus species, including this taxon, for medicinal purposes. Seed predation by rodents also seems to be a problem at two of the colonies, even the plants are eaten in very dry years. The type locality was depleted through intense illegal collecting.