Testosterone plays a key role in the development of the male reproductive organs, determines the development of the male external genitalia and the anogenital distance in males and females. The measurement of the anogenital distance is simple, non-invasive, cost effective and may be used as a surrogate for serum testosterone levels. The present study was conducted to determine the relationship between the total serum testosterone levels, anogenital distance, stretched penile lengths, birth weights and lengths in term neonates at Obafemi Awolowo University Teaching Hospital Complex, Ile-Ife. The study was prospective and cross-sectional. The data were obtained between July 1, 2017 and October 30, 2017 on consecutive term neonates delivered at estimated gestational age of 37-42 completed weeks. The neonates were recruited within the first 72 hours of life. Information on each neonate was recorded in a proforma. The data recorded for each baby included the estimated gestational age, birth weight, birth length, occipitofrontal circumferences, anogenital distance in male and female neonates and stretched penile length in male neonates. The total serum testosterone concentration was assessed using the Enzyme Linked Immunosorbent Assay kits. Data were analysed using the Statistical Package for Social Science for Windows version 20. Pearson’s correlation coefficient (r) between total serum testosterone levels stretched penile lengths, anogenital distance values, birth weights, lengths and occipitofrontal circumferences were determined.