This study investigated the extent of movement, habitat use and foraging behaviour of the lesser hairy-footed dunnart Sminthopsis youngsoni, a small (9 g) insectivorous marsupial, in the dunefields of the Simpson Desert, western Queensland, Australia. Radio-telemetry was used to track nightly movements of dunnarts while foraging and to determine their diurnal resting places. Both males and females travelled comparatively long distances while foraging (mean distance 412 m per night), but some males travelled much further (>2 km in a night). Females travelled frequently between the swales (interdunal valleys) and dune tops in the breeding season (spring), but remained in the swales in the colder months, whereas males were restricted mostly to the swales throughout the year. Females probably travel to the dune tops in response to increased seasonal food resources (invertebrates), at a time when their energy requirements are high (reproduction and lactation) and mobility may be restricted (with pouch- or nest-young). Long-distance movements and low rates of recapture (<10%) indicate that this species is serially nomadic and is able to move to areas of greater resource availability when local resources are depleted. We suggest that the ability to travel long distances in search of food is a successful strategy for this species, resulting in its persistent abundance in an environment where food resources are often patchy and unreliable.