At each 8 on an average 92 (body weight 615 +/- 49 g) and 120 days (b.w. 1.8 +/- 0.40 kg) old fetuses as well as at 6 newborn lambs (b.w. 2.8 +/- 0.65 kg) the concentration of ascorbic acid in the plasma, in the amniotic- and allantois-fluid, in the fetal and maternal part of the placenta and in 13 tissues was analyzed. The highest concentration in the plasma (73 +/- 11 micrograms/ml) was determined in the newborns. The concentration in the amniotic-fluid decreased and that in the allantoic-fluid, the adrenals and the fetal part of the placenta increased in the course of growth. In the cerebrum, the cerebellum, the brain stem, the lungs, the heart, the kidneys, the M. longissimus and the M. semimembranosus the concentration diminished during the fetal growth. In the liver, the spleen and the pancreas the concentration was similar. The function of the ascorbic acid during the fetal development is discussed. The results are compared with those at human, pig and calf fetuses. In analyzing the ascorbic concentration in fetal body fluids of ungulates the high concentration of fructose as an influence-factor in the usual applied methods has to be considered.