Little is known about the dynamics of fertility transition in South Africa, though recent studies have begun to shed light on demographic changes in the country. This study presents trends and patterns of fertility observed in a rural South African population. Various demographic and statistical techniques were used to examine fertility patterns in a population of 21,847 women in a rural KwaZulu-Natal (KZN) demographic surveillance area. These are compared with patterns seen in another South African rural population under demographic surveillance, and with data from the 1998 South Africa Demographic and Health Survey. Findings are interpreted in light of contraceptive use patterns and HIV prevalence in the population. In South Africa, the end of the fertility transition is now in sight. In rural KZN, where national fertility levels are highest, fertility has declined rapidly for about two decades and would have reached below replacement level in 2003. While fertility has declined rapidly among all women over age 18 years, fertility levels among adolescents have not changed in decades. Although most adolescents in rural KZN were sexually active (60%), few had ever used contraception (20%). High HIV seroprevalence appears to explain a small part of the fertility decline (12%); however, this effect is likely to grow in the near future as the HIV/AIDS epidemic continues in South Africa. If the current trends continue in the future, below replacement fertility, together with high mortality due to AIDS, it could soon lead to negative natural population growth in rural South Africa. (Afr J Reprod Health 2004; 8[2]: 38-54 )