The burden of chronic conditions is increasing rapidly in low- and middle-income countries. Chronic conditions require long-term and continuous care, including for patients transferring between facilities. Patient transfer is particularly important in the context of health service decentralization, which has led to increasing numbers of primary care facilities at which patients can access care, and high levels of migration, which suggest that patients might require care at multiple facilities. This article provides a critical review of existing evidence regarding transfer of stable patients receiving primary care for chronic conditions. Patient transfer has received limited consideration in people living with HIV, with growing concern that patients who transfer are at risk of poor outcomes; this appears similar for people with TB, although studies are few. There are minimal data on transfer of patients with non-communicable diseases, including diabetes. Patient transfer for chronic conditions has thus received surprisingly little attention from researchers; considering the potential risks, more research is urgently required regarding reasons for and outcomes of transfers, transfer processes and interventions to optimize transfers, for different chronic conditions. Ultimately, it is the responsibility of health systems to facilitate successful transfers, and this issue requires increased attention from researchers and policy-makers.