The purpose of this study is to determine the normal position of anal opening in newborns using Anal position index (API) and the correlation between API and body length and body weight of the subjects. It is a prospective study that covered a period of one year, from May 2006 to April 2007, at Jos university teaching hospital. Four hundred full term newborns (within 24 hours of life) without gross perineal malformations were studied. API, defined as the ratio of ano-fourchette (ano-scrotum in males) distance to coccyx-fourchette (coccyx-scrotum in males) distance is calculated in all cases. To obtain these distances a thin transparent adhesive tape was placed longitudinally across the perineum, extending from the coccyx to the fourchette (scrotum). The above distances were marked out using ink markers on the transparent adhesive tape. The body weight and body length of the subjects were also obtained. The mean API in females was 0.48+ 0.07 and in males was 0.58+ 0.06. The mean + SD was considered as the normal range for anal position. Anterior displacement was present in twelve newborns (3%) i.e. those with API below mean + SD. Using Pearson correlation coefficient, there was no significant correlation between API and the body length and body weight of subjects.