Agrotourism is widely advocated as a useful strategy to develop mountain agriculture and improve farmers’ income and quality of life. However, the relationship between agriculture and tourism is complex, and the extent to which tourism benefits farmers remains uncertain. This paper examines the relationship between agriculture and tourism and assesses to what extent agrotourism benefits farmers in Phu Ruea district, a popular tourist destination in the mountains of northeast Thailand. The Phu Ruea agrotourism system generated gross income for the district of almost US$ 16 million in 2014. About 80% of this income came from sales from specialty-crop farms and of tourism services operated by the households of local farms. The agrotourism system also created many employment opportunities for local people. There were 1500 people directly involved in the system, 90% of whom were farmers or members of farm households. Thus, there is no doubt that many local farmers derive significant benefits from their involvement in the agrotourism system. Although the Phu Ruea agrotourism system can be seen as a successful strategy for developing mountain agriculture, agrotourism is not a magic strategy to solve all the problems of rural development in the mountains. Only some localities are attractive to tourists, and only some farmers have the knowledge, skills, and resources to take advantage of the opportunities offered by tourism.