Mating behavior, parturition and mother-offspring relations of addax (Addax nasomaculatus), an antelope native to the deserts of North Africa, were studied in captivity at two Texas ranches and the Oklahoma City Zoo between July 1977 and August 1978. Ad libitum and focal animal sampling techniques on 7 adult males, 37 adult females (of which 7 were in labor) and 27 individuals under 1 year of age formed the basis of this study. Addax courtship behavior was similar to that of other Hippotraginae; the major components included mating whirl-around, "Laufschlag" and flehmen. Estrus lasted approximately 24-48 h. Copulation was almost exclusively by alpha males. Pregnant females attempted to isolate from conspecifics prior to parturition. However, alpha males in captivity maintained a close spatial association with such females and exhibited courtship behavior toward them. Females were restless during labor, characterized by alternating bouts of lying and standing. Lying postures during labor were similar to resting postures. Mothers removed and consumed the amniotic sac and placenta. During the first 3 days post-partum, alpha males were overtly aggressive toward neonates under captive conditions. Addax calves showed the prone response and lying-out behavior lasting until 11-14 days and 6-9 weeks post-partum, respectively. Calves formed creche or kindergarten groups. Calves suckled while standing until 15 weeks of age, after which they suckled on their carpal joints. Weaning occurred between 23 and 29 weeks post-partum.