Based on 22-year demographic data, we showed lifespan and lifetime fecundity of wild ring-tailed lemurs (Lemur catta). Ring-tailed lemur is a group-living diurnal prosimian (Primates) in Madagascar. Within the 14.2-ha study area in Berenty Reserve, southern Madagascar, a total of 201 individuals (77 females, 97 males and 27 unknown sexes) were born for the 10 years from 1989 to 1998 and all of them died by 2011. Because ring-tailed lemur is a male-biased dispersal species, all males emigrated from their natal groups when they reached sexual maturity (3-5 years old). Therefore we could not know the exact lifespan of males, although some males reached at the age of 13 in the area. The mean lifespan of females was 4.8 years and the maximal lifespan was 20 years. Although some females gave birth first at the age of 2, most females gave birth first at the age of 3-4. Most females gave birth annually and the maximal lifetime fecundity was 13 offspring (mean: 4.5 offspring). These results suggest that lifetime fecundity of wild ring-tailed lemurs may be highly variable among females.