A new approach to Aegean ivory working, described in this article, demonstrates that in addition to elephant tusk, carvers made use of hippopotamus ivory throughout the Bronze Age. A brief introduction describes the background to the present study and the methods adopted here. The characteristics of elephant ivory and hippopotamus ivory are summarised and examples are given which show how morphological or structural features visible in finished objects enable us to identify the kind of ivory present. The central section presents a range of objects identified, during recent research, as made from hippopotamus ivory. These include prepalatial seals, inlays ranging in date from MMI toLH IIIB, certain Mycenaean plaques and warrior heads. Frequently it is possible to determine how these objects were made, less often why hippopotamus tusk was used. The final sections discuss the question of ivory sources and attempt to draw together the various strands of evidence for ivory working in the Aegean Bronze Age.