For many smallholder farmers in East and Southeast Asia, farming represents a decreasing share of their income-generating activities, leading to increasing limits to investing family labour in farming. This process has been particularly marked in regions where farmers face limited access to land, water and markets. This study asks whether irrigated farms in central Thailand are on a similar pathway. It analyses how these farms have evolved to face existing constraints and their future prospects. The farms have adapted to constraints including lack of fresh water in the dry season, floods, and sometimes insufficient labour. In almost all farming families, farming is still the main income-generating activity for at least one household member. Most of the farmers involved in fish and shrimp farming had already identified a successor in their family or considered it was possible. This was also the case of rice farmers who had made quite high investments in their farms, most of whom cultivated relatively large areas. However, another group of rice farmers had become trapped in a vicious circle of low farm profitability, the increasing age of the farmers and the fact their farms held little attraction for younger generations. Thai agricultural policies did not provide sufficient means to break this cycle. The future of these vulnerable rice farms thus appears to be uncertain. Breaking this cycle may require a comprehensive approach that explicitly addresses the issue of farm structure.