The Bay of Biscay is an oceanic region closely related to cetaceans. It was from localities around these shores that a long whaling tradition started in the XI century. For more than 600 hundred years the Right whale was caught along these coasts until the decline of whaling in the XVIII century. Modem whaling started in Spain at the beginning of the XX century in the Gibraltar Straits. In the second half of the century whaling activity continued in the north west of the Iberian Peninsula. The target species were sperm and fin whale. The interest in cetacean studies on the Spanish coast goes back to the XVIII century with the works of pioneers such as Sarmiento and Comide and continued with the monographic works by Graells and Cabrera. Since the last quarter of the past century an extraordinary boom in the number of studies on cetaceans in the Bay of Biscay has taken place. About thirty cetacean species ha ve been reported in the Bay of Biscay, seven belonging to Mysticeti and twenty three to Odontoceti. Precise knowledge on the biology, distribution and migratory pattems are restricted to some of them whilst absolute abundance estimations are lacking for the majority of the species. Further research is needed in these areas. One of the main concems for the conservation of cetacean populations in the Bay of Biscay is the interaction with fisheries. Other threats are related to the degradation of the marine environment due to chemical waste and the increase in noise pollution. Several conventions deal with the management and conservation of cetaceans. At the European and Spanish level, there are also several regulations conceming the protection of the local populations and their habitats. A Spanish Decree on whale watching is in an advanced state of development. Humans and cetaceans are both part of complex marine ecosystems. For an ecosystem approach to the management of the marine environment it is essential to know the role of all components and the consequences of the human impacts.