Background and objectives: Pregnancy period is one of the most risky periods of women’s life  and nutrition is one of the most important factors related to maternal and foetal health .The aim of this semi-experimental study was evaluating  the  effect of educational intervention on women knowledge and  their attitude towards  nutrition in pregnancy period.

Materials & Methods: The samples were  80 pregnant women selected by cluster sampling  method in Gorgan health service centers. Data collected by a valid and reliable questionnaire completed by samples during pretest. Then an educational program has done, during 2 hours. Two months later, participants completed the same questionnaire as post test. data were analyzed by Kruskal –Wallis ,  Mann-Whitney and Pierson correlation SPSS software V 11.5, confident interval was(p <0.05).

Results: Results showed that level of knowledge was low in 51.5%  of samples and only 9.1 percent had high  level of knowledge in pretest. Finally,  Level of knowledge  and attitude  increased dramatically after post test.

Conclusion: According to the results it seems necessary to have educational interventions for pregnant women in order  to increase their knowledge and attitudes towards their nutrition during pregnancy period   and as a result to promote women and society health.