Objective: the Zishen Yutai pill (ZYP) is one of the most commonly used Chinese medicines to prevent miscarriage. However, its safety during pregnancy remains ill-defined. In this study, we aimed to investigate the potential reproductive toxicity of ZYP on embryo-fetal development. Methods: various doses of ZYP were given to pregnant rats (6, 12 and 24 g kg(-1) d(-1); i.e. 24x, 48x and 96x clinical doses) and rabbits (1.5, 3.0 and 6.0 g kg(-1) d(-1); i.e. 6x, 12x and 24x clinical doses) by intragastric administration for the period from implantation to hard palate closure. Physiological saline and cyclophosphamide were used as negative and positive controls, respectively. Maternal effects on weight loss, implantation failure and fetal resorption as well as effects on fetal physical growth and congenital malformations were recorded. Results: both maternal and fetal toxicities were observed in rats and rabbits after cyclophosphamide exposure, including lower maternal weight (not in rabbits), decreased rate of live fetuses, increased rate of fetal resorption, inhibited fetal physical growth and higher rate of malformation. However, adverse effects such as significantly lower extra-uterine weight gain and decreased food intake during GD6-7 were only detected in rats after exposure to ZYP at the dose of 24 g kg(-1) d(-1), while no severe effects were found in all ZYP treated rabbits. Conclusions: ZYP exhibited no reproductive toxicity on embryo-fetal development at the dose of 12 g kg(-1) d(-1) for rats and 6 g kg(-1) d(-1) for rabbits. Consequently, ZYP can be safely used at the clinical dose.