The paper addresses the claim that traditional Tibetan society is anomalous among peasant preindustrial societies in that it has experienced population decline since the 7th century A.D. Even though Tibet was a relatively affluent society, psychological and social factors are claimed to have substantially reduced fertility levels. The paper challenges this position and argues instead that Tibetan fertility was/is moderately high. It also suggests that very high levels of fertility were not necessary in preindustrial peasant societies to balance high mortality and produce homeostasis or slight growth. [demographic anthropology, peasant fertility, demographic transition theory, Tibet, Nepal]