Objective:To investigate the effects of comparatively high doses of diminazene aceturate on the reproductive performance of female rats in the early stage of pregnancy.Methods: After oestrus synchronisation and successful mating,20pregnant female rats were randomly divided into four groups (A-D). Group A rats served as the control and were given single intraperitoneal injection of0.5mL sterile water (vehicle only) while groupsB, CandD rats were given single intraperitoneal doses of7, 14and 21mg/kg body weight diminazene aceturate respectively, on day 7 of pregnancy. The gestation length, litter size and weight at birth, and areas of foetal resorption in the uterus were determined post partum. The post-implantation survival index (%) and the gestation index (group %) were also evaluated for rats in all the groups.Results: There was a graded increase in the number of observed resorbed foetuses as the dose of diminazene aceturate was increased, although only groupsC(14 mg/kg) and D (21 mg/kg) revealed a significant decrease(P<0.01, ANOVA) in the post implantation survival index of rat embryos. There was also a significant decrease(P<0.05) in the litter weights of rats in groups C and D.Conclusions:Although the pregnant rats showed no overt signs of systemic toxicity even at the highest dose of 21mg/kg body weight diminazene aceturate in this study, it was concluded that the use of high doses of diminazene aceturate in an effort to combat resistant trypanosomes could have adverse reproductive effects on female animals in the early period of pregnancy.