Background and Aim: Urinary tract infection (UTI) is one of the most frequent difficulties in women, and because of the changes which take place in body conditions in pregnancy, pregnant women are more susceptible to it; and due to its potential effects on mothers and the fetus, UTI is considered very important. The aim of this study is to determine Knowledge, Attitude and Behavior of pregnant women based on the Health Belief Model (HBM).Materials and Methods: This descriptive- analytic study has been conducted on 110 pregnant women visited health houses staff in Behbahan city. The tools for collecting information was a multi sectional questionnaire consisting of demographic information, knowledge, attitude and behavior which its validity and reliability were ensured previously. Data were analyzed by SPSS software in significance level of P<0.05.Results: The mean age of the pregnant women in this study was 25 4.68.30.9% of samples had good knowledge, 46.4% had good perceived barriers, 94.5% had good perceived benefits 90.9% had good perceived susceptibility, 84.5% had good perceived severity and 35.5% had good behavior. There was a meaningful difference between employed people and housewives in regard of knowledge, knowledge did not relate to income. There was a meaningful positive correlation between knowledge and perceived barriers, perceived benefits perceived susceptibility and behavior.Conclusion: The results revealed that the level of knowledge, attitude and health behavior of most of the pregnant women presented in the study were moderate in the field of prevention of urinary infections; and in this respect some suggestions have been made as: to hold education classes to raise women s knowledge, attitude and health behavior on prevention of urinary infections by delivering speech and group discussion, to present books and educational pamphlets and to optimize Radio and TV education programs by experts.