Deficiency of 3beta-hydroxy-delta5-C27-steroid dehydrogenase (3beta-HSDH), the enzyme that catalyses the second reaction in the principal pathway for the synthesis of bile acids, has been reported to present with prolonged neonatal jaundice with the biopsy features of neonatal hepatitis. It has also been shown to present between the ages of 4 and 46 months with jaundice, hepatosplenomegaly, and steatorrhoea (a clinical picture resembling progressive familial intrahepatic cholestasis). This paper reports two children with 3beta-HSDH deficiency who developed rickets during infancy and did not develop clinically evident liver disease until the age of 3 years. Bile acid replacement resulted in considerable clinical and biochemical improvement. The importance of thorough investigation of fat soluble vitamin deficiencies in infancy is emphasised.