A teratogenicity study on miporamicin (MPM) was performed in New Zealand White rabbits. Following suitable dose range finding experiments, 60 mated rabbits were randomised into 4 treatment groups, each containing 15 animals. These animals were dosed once daily, by oral gavage, over days 6-18 inclusive of gestation, where the day of mating was designated as day 0. The dose levels applied were 0, 50, 100 and 200 mg/kg/day. A standard dose volume of 5 ml dosing suspension per kilogram body weight was applied, the vehicle being an 0.5% solution of carboxymethylcellulose in distilled water. There was an effect on maternal food consumption at 200 mg/kg/day: cessation of consumption by over one quarter of the animals in the group. Under the conditions of this study, MPM had no effect on the outcome of pregnancy at dose levels of up to 200 mg/kg/day. There was generally no significant effect on either the mother or the conceptus at 100 mg/kg/day.