This study is an investigation into The problems of interdenominational marriages among members of orthodox churches in Kaduna State'. This study was occasioned by the increase of divorce and other related vices in marriage due to interdenominational unions among couples of orthodox churches in Kaduna State. A survey of the institution of marriage from the Biblical period to its practice among Christians today constitutes the background to this study. The prevalent cases of divorce among couples in interdenominational marriages constitute the problem of the study. Five objectives aimed at identifying the problems associated with interdenominational marriages were stated. Five questions were asked in line with the objectives of the study. Following the research questions, five null hypotheses were stated to free the study from preconceived results. A total number of 1080 copies of the questionnaire were administered to Christians in orthodox churches in nine local government areas covered by the study. Eight hundred and fifty (850) copies of the questionnaire were returned out of which seven hundred and fifty (750) were found useful for the study. The data collected with the questionnaire were analyzed with means, percentages, frequencies and two-tailed t-test statistics. The result of the study was presented in tables. The demographic variables of the questionnaire were analyzed with frequency and percentage statistics, while the hypotheses were tested with means, standard deviations, one way analysis of variance (ANOVA) and two-tailed t-test statistics. The conclusion from the study showed that interdenominational marriages often v have problems that could lead to the separation of the partners. Also, recommendations that suggest strict adherents to Biblical teaching, maintenance of marriage harmony, respect for the institution of marriage as ordained by God and a consideration of the problems associated with interdenominational marriages before going into it were made as solutions to the problem.