The purpose of this research was to study the age of onset of puberty and its procedure among the male students aging from 7 to 14 years old in the town of Hamadan during the spring of 1995.

The method was cross-sectional and non-interventional and was performed by examining 600 students.

The criteria of the puberty were the growth of genitalia and public hair.

Regarding the statistics since there were no meaning full differences between the age of onset in different parts of the parts of the town and considering the socioeconomical levels, it may be concluded that the economical factors play no particular role on the onset and procedure of puberty.

In all the age levels, growth of genitalia was observed more than the growth of public hair

In this study the average age of genitalia growth on set was 10.5 years old and of the public hair 11.7 years old.

Until the age of 14, 100% of male students had shown genitalia growth and 94.4% public hair growth as the signs of puberty.