Background: The average age of menarche varies from country to country due to regional variation and different factors, including genetic and environmental factors that affect the onset of menarch. This study performed to survey relationship between nutrition and physical activity with menarche age of girls in Ahvaz city.

Materials and Methods: This survey is a cross-sectional study that was conducted on 1249 female students 8-15 years in 2012- 2013 year. Participants were selected by random cluster sampling from 4areas and 16 elementry and middle and high schoolsin Ahvaz city. The data were collected based on interviews and questionnaire (food frequency and physical activity). After collecting the data, then they were encoded and analyzed by SPSS16 software  and descriptive and analytic statistics.

Results: The mean of age at menarche in girls in Ahvaz was 11.86±1.07 and age at menarche was not associated with nutrition and physical activity.

Conclusion: Based on these findings, significant association between nutrition and physical activity and age at menarche (p<0.001)was not observed.