In low- and middle-income countries, patients may travel abroad to seek better health services or treatments that are not available at home, especially in regions where great disparities exist between the standard of care in neighbouring countries. While awareness of South–South medical travels has increased, only a few studies investigated this phenomenon in depth from the perspective of sending countries. This article aims to contribute to these studies by reporting findings from a qualitative study of medical travels from Cambodia and associated costs. Data collection primarily involved interviews with Cambodian patients returning from Thailand and Vietnam, conducted in 2017 in the capital Phnom Penh and two provinces, and interviews with key informants in the local health sector. The research findings show that medical travels from Cambodia are driven and shaped by an interplay of socio-economic, cultural and health system factors at different levels, from the effects of regional trade liberalization to perceptions about the quality of care and the pressure of relatives and other advisers in local communities. Furthermore, there is a diversity of medical travels from Cambodia, ranging from first class travels to international hospitals in Bangkok and cross-border ‘medical tourism’ to perilous overland journeys of poor patients, who regularly resort to borrowing or liquidating assets to cover costs. The implications of the research findings for health sector development and equitable access to care for Cambodians deserve particular attention. To some extent, the increase in medical travels can stimulate improvements in the quality of local health services. However, concerns remain that these developments will mainly affect high-cost private services, widening disparities in access to care between population groups.