The objetive of this research work was to study the effect of the frequency of copulation during the post-ovulatory estrous on the embryonic mortality in alpacas. Forty four female alpacas were selected having a post-partum sexual rest >20 days and bearing in the ovaries a pre-ovulatory follicle >7 mm of diameter. Animals were mated (time of coitus: >15 minutes) using a male with proven fertility and received 6 g of busereline i.m. after copula to ensure ovulation. Three experimental groups were then ramdomly organized: the first group (S 1 , n = 14) did not receive additional matings, the second gropup (S 2 , n = 15) received an additional mating on day three post-ovulation, and the third group (S 3 , n = 15) received additional matings on days three and four postovulation. Ovulation was confirmed through ultrasound images by disappearance of the pre-ovulatory follicle 42 hours post-mating and the presence of a corpus luteum on day 5 post-ovulation. In addition, the size of the corpus luteum, morfological changes of the uterine horns and presence of an embryo were recorded on days 13-14 and 19 postmating. These observations were complemented with the observation of sexual receptivity using a male on days 6, 13-14, 19 and 26 post-mating. Ovulation rate was 91%. There was a higher tendency on embryo survival at day 19 post-mating in those alpacas that received an additional mating on days 3 (S 2 = 80%) and 3 and 4 (S 3 = 85%) post-ovulation than in those animals without additional mating (S 1 = 75%). An additional study in four inducedovulated alpacas was done to detect fertilized ova at days 2, 3 and 4 post-ovulation. Recovery of the fertilized ova from oviduct was possible only until day 3 post-ovulation. Key words: alpaca, embryonic mortality, post-ovulation RESUMENEl presente trabajo tuvo como objetivo estudiar el efecto de la frecuencia copulatoria durante el celo postovulatorio sobre la mortalidad embrionaria en alpacas. Se seleccionó 44 alpacas hembras con descanso sexual postparto >20 días y con presencia de un folículo preovulatorio >7 mm de diámetro. Los animales fueron servidos con macho de fertilidad comprobada (tiempo de cópula: > 15 minutos) y se les aplicó 6 g de buserelina para asegurar la ovulación. Se formaron 3 grupos experimentales al azar: el primero (S 1 , n = 14) no recibió servicio adicional, el segundo (S 2 , n = 15) recibió un servicio adicional el día 3 postovulación, y el tercero (S 3 , n = 15) tuvo servicios adicionales los días 3 y 4 postovulación. Se confirmó la ovulación mediante observación ecográfica del ovario a través de la desaparición del folículo preovulatorio a las 42 horas postservicio (del primer