Studies of animal culture have not normally included a considerationof cetaceans. However, with several long-term field studies nowmaturing, this situation should change. Animal culture is generallystudied by either investigating transmission mechanismsexperimentally, or observing patterns of behavioural variation inwild populations that cannot be explained by either genetic orenvironmental factors. Taking this second, ethnographic, approach,there is good evidence for cultural transmission in several cetaceanspecies. However, only the bottlenose dolphin(Tursiops) has been shown experimentally topossess sophisticated social learning abilities, including vocal andmotor imitation; other species have not been studied. There isobservational evidence for imitation and teaching in killer whales.For cetaceans and other large, wide-ranging animals, excessivereliance on experimental data for evidence of culture is notproductive; we favour the ethnographic approach. The complex andstable vocal and behavioural cultures of sympatric groups of killerwhales (Orcinus orca) appear to have no paralleloutside humans, and represent an independent evolution of culturalfaculties. The wide movements of cetaceans, the greater variabilityof the marine environment over large temporal scales relative tothat on land, and the stable matrilineal social groups of somespecies are potentially important factors in the evolution ofcetacean culture. There have been suggestions of gene-culturecoevolution in cetaceans, and culture may be implicated in someunusual behavioural and life-history traits of whales and dolphins.We hope to stimulate discussion and research on culture in theseanimals.