Neonatal jaundice has been suggested as a perinatal risk factor for autism spectrum disorder (ASD). We examined UGT1A1 polymorphisms to assess the potential of neonatal jaundice as a risk factor for ASD in children by using DNA extracted from preserved umbilical cord. In total, 79 children with ASD were genotyped for "UGT1A1*28" (c.-41-40dup), "UGT1A1*6" (c.211 G > A), and "UGT1A1*27" (c.686 C > A). The allele frequency of "UGT1A1*6" (OR = 1.34, p = 0.26) and "UGT1A1*28" (OR = 0.80, p = 0.54) and the prevalence of "UGT1A1*28/*6" diplotypes did not differ significantly from those in the control population. No "UGT1A1*27" allele was detected in the subjects. ASD symptom assessment scores were not associated with "UGT1A1*28/*6/*27" genotypes or "UGT1A1*28/*6" diplotypes. These results suggest that neonatal jaundice is not significantly associated with ASD.