Slender-tailed meerkats or suricates, Suricata suricatta, are small, gregarious and largely insectivorous mongooses which inhabit the arid and semi-arid areas of southern Africa. We describe four elements of co-operative rearing of the young: 1. babysitting at the den; 2. creching on foraging trips; 3. provisioning with prey items away from the den; and 4. allonursing, including spontaneous lactation. Individual band members differed markedly in contributions to co-operative rearing. All adults and yearlings guarded the den and helpers actively defended young against predators. Breeders babysat significantly less than did non-breeding adults. Differences in age–sex class contributions were also evident in creching behaviour. The feeding of kittens by provisioners extended from soon after their first emergence from the den at 2–3 wk of age to effective foraging independence at 10–12 wk. Breeding females initially contributed little care other than nursing. Allonursing occurred in six of 25 closely observed litters, including three incidents of spontaneous lactation when subordinates nursed the young of higher-ranking females. Such co-operation is likely to be critical to the survival of these highly sociable mongooses in a semi-arid environment such as the Kalahari where food availability can fluctuate enormously.