Background and Aim: Growth spurt during adolescence, particularly the occurrence of menstruation in girls, increases their nutritional needs. The present study aimed at determining the effect of nutrition education on nutritional knowledge and Behavior of secondary school female students in the city of Birjand. Materials and Methods: In this quasi-experimental study, 120 second grade secondary students in Birjand in 2012 were selected through two-stage cluster sampling method and were randomly divided into intervention and control groups. Data collection tool was a questionnaire which was completed by the students both before and one month after intervention. The obtained data was analyzed by means of descriptive and analytical statistics including chi-square, independent and paired t-tests, and ANOVA at the significant level of 0.05 using SPSS software (V:16). Results: Mean scores of nutritional knowledge in the intervention group after education increased from 21.35±4.57 to 26.66±4.4 (P>0.001) and their mean performance increased from 1.84±7.39 to 1.86±8.31 (P<0.04). A significant difference in mean scores of knowledge between the control group and the intervention group was observed (P<0.05). However, performance mean difference between the two groups was not significant. Conclusion: Education through lecture and asking/answering questions can significantly increase adolescents’ awareness and to some extent, their nutritional performance, although more effective methods are advised to promote the situation.