It has been generally accepted that hwangryunjihwang-tang (h-tang) is a useful prescription for treating polydipsia and to prevent obesity induced by a high-fat diet. The aim of this study was to clarify whether h-tang improved reproductive dysfunction caused by obesity in mice. Mice were fed a high density protein and lipid diet for 4 weeks, followed by administration of h-tang at 480 mg/kg body weight per day for 4 days. Thereafter, changes of body weight, ovulation rate, in vitro and in vivo fertilization, embryonic development and implantation rate were measured. H-tang markedly reduced the body weight of obese mice fed a high-fat diet, but not mice fed a normal diet. H-tang significantly improved ovulation rates, in vitro and in vivo fertilization rates and embryonic development. These results indicate pharmacological reversal of reproductive dysfunction caused by obesity, perhaps by adjusting internal secretions and metabolic functions.