The main objective of this paper is to explain fertility behavior of Kurd and Turk women using theoretical framework for the explanation of ethnic fertility differentials. The data for this paper is drawn from a survey on ethnicity and fertility which was conducted in Orumieh district in 2007, and covered households resident in the district. Information was collected from a sample of 768 households and 739 ever-married women identified in the households. A combination of sampling techniques including multistage clustering and systematic random sampling were employed. The analysis revealed that although ethnic fertility differentials have narrowed over time, Kurd women experienced higher fertility than their Turk counterparts. For example, at the time of the survey, Kurd women on average had significantly higher children ever born (3.3) than Turk women (2.2). The impact of ethnicity on fertility was found to be contextual, and varied across cohorts. The results of multiple classification analysis indicated that applying a comprehensive approach in analyzing ethnic fertility differentials, at least in the study area, provides a better explanation as compared with using only the characteristic hypothesis or cultural-normative approach.