Purpose: The purpose of this study was to identify the effects of husband and wife compatibility and self efficacy on health promotion behavior and define the main factors influencing health promotion behavior in middle aged women. Method: Using a structured questionnaire, data were collected from 311 middle aged women. Descriptive statistics, Pearson correlation coefficient, Stepwise multiple regression with SAS package were used for data analysis. Results: The mean score of husband and wife compatibility was 3.55(${pm}.56$), self efficacy was 3.51(${pm}.54$), and total health promotion behavior was 2.91(${pm}.37$), with scores for subcategories as follows: interpersonal support 2.86(${pm}.59$), self-actualization 2.74(${pm}.56$), nutrition 2.56(${pm}.63$), health responsibility 2.32(${pm}.60$), stress management 2.28(${pm}.51$), and exercise 1.87(${pm}.74$). Husband and wife compatibility, and self efficacy were positively related to health promotion behavior and all subcategories of health promotion behavior. Also husband and wife compatibility were positively related to self efficacy. The major factors that affect health. promotion behavior in middle aged women were husband and wife compatibility, self efficacy, economic level, and religion, which explained 32.6% of health promotion behavior. Conclusion: The results indicate that health promotion behavior may be increased through interventions directed at improving the husband and wife compatibility.