The movements of 17 eastern sarus cranes Grus antigone sharpii in Cambodia and Vietnam were tracked during both wet and dry seasons in 1998−2002 and 2015−2017, revealing previously unknown but important sites. Crane breeding territories were located in Cambodia’s northern dry deciduous dipterocarp forests, with territories of cranes captured in the Tonle Sap basin located further west and more likely to fall within protected areas than those captured in the Mekong Delta. During the non-breeding (dry) season, cranes returned to sites in which they had originally been captured. Most cranes initially used a different part of the same floodplain in the early stages of the dry season, but cranes from the Mekong Delta that nested west of the Mekong River would initially stop in the eastern Tonle Sap floodplains before continuing to the Mekong Delta floodplains. Protected area coverage of key dry season habitat within the Tonle Sap basin was lower than in the Mekong Delta. Out of 5 juveniles tracked in 2015/2016, 1 disappeared, 1 died and 1 was injured; 1 adult also disappeared. All mortality and disappearances occurred during the wet season and at least 1 mo after capture. Persistence of the eastern sarus crane will require improvement of protected area coverage of both breeding areas and previously unknown but important sites used during the dry season.