The sustainability of family farming and its capacity to respond to global changes are widely debated. Based on a survey of 40 farms on the Saïs Plain in Morocco, this article shows how family farms which implemented similar rainfed crop–livestock production systems 45 years ago have evolved differently based on farm characteristics and the variety of natural, economic and political changes they have faced over that time. The survey sample was constructed to cover the wide diversity currently found with regard to the structure, production choices and access to resources (water, land, capital) of local family farms. Four initial farm types were identified based on their access to land, which ranged from private property to collective land tenure. These farms may be grouped today into three main types based on their production activities: mixed rainfed crop–livestock farms, diversified farms combining rainfed and irrigated crops (vegetables and fruit orchards), and specialized irrigated farms. Seven types of development pathways leading farms from their initially similar to their currently diverse situations were identified. The critical determinants were whether and how farms were able to access water and capital resources to acquire land and innovate with high-value crops. This study illustrates that most family farms have capacity to evolve in different ways. However, competition over access to resources (ground water, labour, land) and markets, both between family farms and with locally based agribusiness firms, are a source of uncertainty weighing upon the development dynamics and future of family farms.