Communal roosting is an interesting behaviour observed in many hornbills. We located seven roost sites of Great Hornbill (Buceros bicornis) and Wreathed Hornbill (Rhyticeros undulatus) at Buxa Tiger Reserve, India. We monitored these sites from 2018 to 2023 to determine roosting patterns and yearly trends in numbers. Two roost sites were regularly monitored in the non-breeding season. In 2022 and 2023, we also carried out monitoring during the breeding season. The hornbill numbers, the sex/age of birds, and the first and last arrival times were recorded. During the non-breeding season, the mean number of Great Hornbills roosting in hill forests was 6 ± 0.78 (range:1–20), while the mean number of Wreathed Hornbills roosting along a riverbank was 42 ± 7.26 (range:1–224). The range in breeding season numbers for Great Hornbills was 1–7 birds, while for Wreathed Hornbill, it was only one bird. Hornbills arrived an hour earlier in winter than in summer. Great Hornbills usually arrived together, close to or after sunset, while Wreathed Hornbill flocks arrived over an extended period, with most arriving 10–40 minutes before sunset. This study highlights the differences between hornbill species in roosting behaviour and habitats used for roosting. Long-term monitoring helps to understand the trends in numbers of hornbills using the roost sites, observe patterns in behaviour over time and potential threats to these critical habitats enabling conservation actions. Monitoring these sites can provide insights into the habitat quality, including any natural or anthropogenic changes in vegetation, such as loss of roost trees.