ABSTRACT: Vaginitis is a common problem for women, especially in reproductive-aged women. It is a worldwide health problem with many side effects but could be prevented by a health-promoting lifestyle related to vagina health. The aim of this study was to determine the factors affecting relapse of vaginitis.In this experimental study, 350 reproductive-aged women with vaginitis were selected from 10 health centers in Kermanshah (Iran) during 2015 and were equally included in the intervention and control groups. To collect data, a researcher-created questionnaire, which included sociodemographic and health-promoting lifestyle questions, was used. The educational intervention was performed over 20 sessions, each lasting 25-35 minutes. An intervention group was educated by face-to-face education, pamphlets, phone contacts, text messages, and social media. Another group continued the routine clinic education and treatment without contacting the intervention group. Data were analyzed through chi-square and a logistics regression model using IBM-SPSS version 20.The results of the study indicated a significant relation between sociodemographic characteristics such as women and their husbands' literacy, job, family size, income, area for each member of family, tendency of pregnancy, body mass index (BMI), and caesarean experience (p<0.001) and vaginitis. In addition, significant relationships between health-promoting lifestyle dimensions and prevention of vaginitis were identified. Relapse after intervention in the intervention group was 27.7% and 72.3% in the control group. According to the logistic regression analysis, chance for relapse of vaginitis in the group that did not receive intervention was more than the same chance in the intervention group (OR=5.14).Health-promoting lifestyle intervention influences prevention of vaginitis. Health-promoting lifestyle, literacy promotion, prevention of caesarian, and obesity are beneficial to improvement in lifestyle dimensions associated with vagina health could be implemented as a successful prevention method. Therefore, it seems that applying a health-promoting lifestyle is essential for a healthy vagina and prevention of vaginitis.