We carried out a retrospective review of infants with biliary atresia splenic malformation (BASM). We found that 56 infants (10.2%) met the criteria for inclusion from a series of 548 infants (from January 1977 to December 2004). Syndromic infants were more likely to be female (P = .04) and to have a higher incidence of antenatal pathology (specifically maternal diabetes; 12.5% vs 1.2%; P < .0001). Situs inversus was noted in 21 (37%) and cardiac abnormalities in 25 (45%) infants. There were no differences in liver histology (eg, degree of liver fibrosis) or in the HLA genotype between BASM and nonsyndromic infants. Five-year and 10-year estimated native liver survival were 46% and 32%, respectively. There were 7 long-term survivors with their native liver and a follow-up of more than 10 years; all were anicteric. BASM is a distinct subgroup, with an implied onset during the embryological phase of organ development.