Some effects of various degrees of zinc deprivation during pregnancy have been examined in dams and offspring. After mating, the dams were fed a biotin enriched, 20% sprayed egg white diet which contained less than 1 ppm zinc. Zinc was provided in the drinking water at one of the following concentrations: 1, 2, 3, 5, 11, or 25 mg/liter. Pups were taken by cesarean section on day 22 of gestation. The dams given insufficient zinc became anorexic, particularly during the latter third of gestation. Anorexia occurred earlier and was most severe at the lowest levels of zinc intake. The decreased food consumption resulted in energy deprivation and at the lowest levels of zinc intake, in protein insufficiency. The total weight gain and rate of weight deposition in the dams were both functions of the level of zinc provided. Fetal growth and extent of zinc deposition into the fetuses were both related to the amount of zinc provided. The responses of dams and fetuses to the extent of zinc deprivation were not equivalent, however. It appeared that there was a sparing of fetal growth at the expense of the dam at very low levels of zinc intake. Conversely, at higher, but still suboptimal levels of zinc, the fetuses still experienced growth retardation although the dams attained a normal weight deposition during gestation.