This paper explores the native-immigrant marriage differentials in Iran. Employing secondary analysis of aggregate and individual data from the Iran 2006 Census, the timing of marriage (Singulate Mean Age at Marriage) and proportions ever married for Afghan migrants and the native born were compared. Then, the native-immigrant marriage differentials among the youth were explained within the structural and cultural adaptation framework. The result indicates a significant difference in marriage behavior between Afghan immigrants and Iranians. Afghans get married at a young age and earlier than Iranians. These differences have been reduced for the second generation Afghans, and there is evidence of convergence of marriage patterns of the second-generation Afghans towards Iranian marriage patterns. Controlling for socio-economic characteristics in multivariate analyses demonstrates that marriage differentials between immigrants and the Iranian native population can largely, though not in full, be explained by low structural adaptation of Afghans or due to their unequal socio-economic situations. The remaining differentials, particularly for first-generation Afghans, may be explained by different marriage markets as well as cultural factors. Overall, this paper demonstrates that native-immigrant differentials in socio-economic characteristics (marriage possibility and conditions), different marriage market dynamics (accessibility), as well as cultural differences (meaning and desirability of marriage) have led to different marriage behaviors of Afghans as compared with Iranians.