History and Objectives: Due to the importance of puberty phenomenon and considering the role of various factors in its onset and progression and in order to define the average age of puberty in female students of Kashan, this study was performed in the curriculum year 1377-1378.

Materials and Methods: A descriptive study was performed on 2300 students at preliminary, intermediary and high school levels by random sampling. The stages of telarch, pubarche and menarche were recognized by physical examination by a resident of gynecology and obstetrics. Characteristics such as weight, height, education, parent’s job and the age of puberty of the mother were evaluated. All the data were recorded. The age of the first menstruation was regarded as the age of puberty onset and its progressive stages were defined according to standards.

Results: Of the 2300 evaluated students in the age of puberty in girls was 12.36±1.24 years and the mode of their age group was 12-17 years. Weight and height were higher in the girls with puberty than those without onset of puberty. The maternal age of puberty in the girls with puberty was 12.5 years. In 74% of the girls, the age of puberty was the same as their mothers. There was no correlation between their age of puberty and the educational level of their father but the age of puberty was related to the educational level of the mother and the parent’s job.

Conclusion: Age of puberty in Kashanian girls is low and shows a decrease relative to the age of puberty in their mothers. Analytical research of recognition of the effective factors in the age of puberty and its stages is recommended.