evaluation of stages and mean age of onset of puberty in boys of yazd

introduction: genetic and health factors along with ethnicity and geographic location are factors that affect the time of puberty onset. the aim of the present study was to evaluate the mean age of onset of puberty and its stages in boys of yazd. methods: this cross- sectional study with random clustering sampling method was conducted on 1018 healthy 9-16 years old male students of yazd. all cases were examined and evaluated for onset and secondary characters of puberty with inspection of the genital region for pubic hair and scrotum and testicular size according to tanner classification. results: the mean age of g2 (onset of testicular growth) and ph2 (onset of pubic hairs growth) was 11.57±1.54 and 12.43±1.07 years. the mean age of g5 (final stage of testicular growth) and ph5 (final stage of pubic hairs growth) was 15.43±0.8 and 15.69±1.1 years. the mean bmi in the early stages of puberty (g2) was 16.32±2.02. conclusion: the mean age of onset of puberty (g2) in boys of yazd was 11.5 years that is similar to other researches in other countries.