In a swine production herd, spontaneous scurvy was observed among piglets 2–3 weeks after weaning. All affected pigs had the same boar as both maternal and paternal grandfather. The affected pigs had only traces of ascorbic acid in blood and tissues as compared to litter mates and other normal pigs. The ratio between the total numbers of normal and affected pigs in the 4 litters concerned was in agreement with a 3:1 segregation, which is characteristic of simple autosomal recessive inheritance in matings between non-affected carriers. Two affected pigs were restored to normal when given ascorbic acid in the diet. Without vitamin C supplement affected pigs died or had to be euthanized. Liver microsomes from an affected pig were unable to synthesize ascorbic acid in vitro with 1-gulonolactone as a substrate, unlike microsomes from normal control pigs.