To identify risk indicators for talipes equinovarus, we compared 175 case children with talipes equinovarus of unknown etiology identified through the Washington State Birth Defect Registry with 1,470 control children sampled from resident live births. Infant gender, maternal smoking, death of a preterm sibling, and marital status were independently related to talipes equinovarus in an analysis based on information from birth certificate records. The findings differed by infant gender. The prevalence odds ratio for maternal smoking was 2.6 (95% confidence interval: 1.6-4.0) in males and 1.4 (95% confidence interval:0.6-3.2) in females.