It was known that in animals, anogenital distance (AGD), an indicator of prenatal androgen environment, was a stabile phenotype that persists throughout life. However, it is not known whether this applies to humans. In this study, we aimed to investigate whether anogenital distance is stable or not in males. We evaluated a total of 130 men targeted for group 1 (fathers) and group 2 (sons) in each 65 participants. AGD, the distance from anus to the posterior base of the scrotum, was measured with digital calipers. Anthropometric characteristics and testosterone levels of groups were recorded. We studied anogenital index (AGI), by dividing AGD by BMI to control bias of the weight and height, which could influence the measurement of AGD. The mean age of fathers was 61.5±10.2 and that of children was 32.1±5.48 (p=.00). The mean AGD scores were 55.46±10.36 vs. 60.21±10.04 (p=.09) and the mean total testosterone levels were 3.6±1.47 vs. 5.45±2.3 (p=.00) in group 1 and 2 respectively. There was no significant difference in height and weight between the two groups. AGD decreases with age, but further longitudinal studies are needed.