Studies on the elephants of the Hoanib River catchment are limited. The most significant research undertaken during a period of drought and civil war inducing a high stress situation for the elephants. The only other reported study was undertaken at the end of the Namibian civil war and focused on elephant range and movement and did not carry out an in-depth analysis of the elephants ecology. The current study examined two distinct populations of elephants separated by an area with a high human population. The average group size of elephant herds in both the eastern and western sections of the catchment has declined steadily from the early 1980s until the present day. Average group size also appeared to be seasonally dependent, with larger group sizes observed during the cold-dry and wet season in the eastern catchment and during the wet and hot-dry season in the western catchment. The social interactions between elephants were investigated in the western section of the catchment only. Associations between different family units were only loose affiliations lacking the strong social bonds reported from other areas of Africa. Adult male group associations were shown to be transient and irregular, with small group size. Keywords: Desert-dwelling elephants, Group size, Movement, social organization.