The continued cultivation of landraces by household farms in centers of domestication and diversity is considered to be an in situ means of conservation of crop genetic resources. However, because in situ conservation has continued into the present does not ensure that this de facto strategy for conserving crop genetic resources will continue into the future. Whether or not traditional varieties continue to be cultivated rests primarily on factors influencing the crop decisions of these household farms. This paper focuses on two questions: 1) what are the significant determinants influencing the household cultivation of traditional wheat varieties; and 2) how do those determinants affect on-farm levels of diversity and the stability of on-farm conservation? To address these questions, we incorporate socioeconom ic/household characteristics, as well as information on agroecological heterogeneity, market access, and perceptions of variety attributes into a household land-use decision model to examine plot-level decisions to cultivate wheat landraces. The results of this research have policy implications at several levels. If policy makers support in situ conservation, information on the househo lds most likely to continue to cultivate landraces, as well as the landraces cultivated by those households, can provide an idea of the likelihood of maintaining the current in situ conservation of crop genetic resources without intervention. Information on these households and on the significant determinants of their landrace cultivation can also provide guidance on the types and levels of intervention necessary, as well as the potential costs.