The purpose of the present study was to develop and estimate the psychometric properties of the Faith in Marital Life Scale as an instrument for evaluation of religious attitudes toward marital relationship. To this end, a sample of 243 students together with their spouses was selected using the cluster random sampling method from among the students of universities in Tehran province. The data collection instruments included the Faith in Marital Relationship Scale developed on the basis of theoretical studies and interviews with successful religious couples, the Sanctification in Marriage Questionnaire, the Manifestation of God in Marital Life Scale (Mahoney, et al, 1999), the Marital Satisfaction Index (Hudson, 1992) and the Islamic Religiosity Scale (Bahrami, Ehsan, 2005). The obtained data were analyzed by exploratory factor analysis, Pearson correlation and independent t-test. At the pilot stage, the content validity and the face validity of the scale were confirmed by experts and by the sample respectively and 19 items were eliminated. The results of the exploratory factor analysis revealed that the 33 remaining items were significantly loaded with 6 factors: religious practice-belief pattern, (lack of) doubt about faith, reliance on God, manifestation of God, religious valuation, and religious responsibility. The results further indicated that the Faith in Marital Life Scale had significant convergent validity with the scores of the Sanctification in Marriage Questionnaire, the Manifestation of God in Marital Life Scale, the Marital Satisfaction Index and the Islamic Religiosity Scale (p<0.001). The correlation of the subjects’ scores in re-administration of the Scale with a one-week interval was significant (r=0.85) signifying good test-retest reliability of the scale (p<0.001). Also, Cronbach’s alpha coefficient was 0.93 for all the extracted questions. Considering these findings, it can be concluded that the Faith in Marital Life Scale is an instrument with appropriate validity and reliability for evaluation of the role of religious attitudes toward marital life among couples.