The health behavior of a pregnant woman, including adequate nutritional behaviors and supply of all the necessary nutrients. The objective of this study was examined the effect nutritional education based on Pender's Health Promotion Model on nutritional behavior of pregnant women referred to health centers in Hamadan city, Iran, 2016. This study was a quasiexperimental study, and its plans for the two groups (experimental and control groups). 100 women referred to health centers in Hamadan city who were experiencing their first pregnancy were randomly assigned to two experimental and control groups. Written informed consent was obtained from all participants. In this study, nutritional education, behavior, within four 45-60 minutes session in two weeks, was performed. Data were gathered using three questionnaires: demographics, Pender’s HPM constructs, and nutritional behavior. The validity and reliability of questionnaires were confirmed. Four educational sessions were performed in the experimental group. Through three stages (before, immediately, and six weeks after interposition) these groups were evaluated. Analysis of the data was performed by SPSS/16, statistical tests such as t-test, paired t-test, chi-square and repeated measurement test was used. Results of this study showed that two groups have no considerable difference in terms of age, education, job, type of housing, family income and sport (P>0.05). The mean scores of the two groups were matched based on Pender's HPM. The scores after the intervention in both nutritional behaviors and Pender's Health Promotion Model components than the control group significantly increased (P<0.001). The results showed that the Pender’s HPM-based training can positively affect and improve the pregnant women’s nutritional behaviors. Therefore, it is recommended that the nutritional behaviors should be changed through promoting people’s knowledge about nutrition during pregnancy. Key-words: Education; Pregnant women; Pender's Health Promotion Model.