congenital clubfoot is the most common birth defect of the musculoskeletal system and affects 1 in every 1000 live births each year.(1) Although there have been numerous studies of investigation, the etiology and pathogenesis of clubfoot remains unknown. To date, no epidemiological studies have been conducted in Peru to assess possible genetic and environmental risk factors associated with this deformity. The purpose of this study was to evaluate specific environmental and socioeconomic factors that may increase the risk of clubfoot. A descriptive clinic-based study was conducted using structured questionnaires given to biological mothers of clinically confirmed clubfoot patients (n=72) and biological mothers of children between ages 0-18 with no first or second degree family history of clubfoot as controls (n=103). Phenotypic data from clubfoot subjects were also collected. We found that males were twice as likely to have clubfoot as females, and half of all clubfoot patients had bilateral clubfoot. There was no significant difference in the rate of left vs. right clubfoot. Infant birth in the winter months correlated with an increased risk of clubfoot (p=0.01476). Maternal characteristics found to be significantly associated with increased risk of clubfoot were young maternal age at conception (p=0.04369) and low maternal education (p=0.003245). Young paternal age also had a correlation with increased risk of clubfoot in the child (p=0.0371). Both paternal smoking (p=0.00001) and the presence of any household smoking (p=0.00003) were strongly associated with an increased risk of clubfoot.