Abstract: This paper describes the history of solitary dolphins in Spain since 1970 and reviews the challenges they present for both their own survival and welfare, and the safety of humans that interact with them. Seventeen solitary common bottlenose dolphins, Tursiops truncatus, have been recognized in Spanish waters, with the majority of these (N=14) in the waters of Galicia (northwest Iberian Peninsula). Some of these solitary dolphins have come to interact with humans, leading to them being referred to as solitary-sociable dolphins, which present particular problems in terms of their management. The different stages of sociability of solitary dolphins are presented and discussed. Two cases from Galicia, the dolphins known as Gaspar and Confi, are presented in detail. The legal frameworks in place to protect cetaceans in Spain are outlined and how these could be used to help protect solitary dolphin welfare is discussed. Human safety also needs to be considered, particularly when people come into close contact with a solitary dolphin either when seeking to interact with the animal or if the dolphin approaches them, for example professional divers working in Galicia. Recommendations are provided for how management plans can be developed for use when a solitary dolphin is present in Spanish waters. These plans could include restricting access by the public to certain areas and implementing flexibility in local fishing practices to help avoid conflict. Education is key to ensure that the public is aware of how to behave appropriately around a solitary dolphin (and cetaceans in general) and to ensure that relevant laws are followed. It is imperative to avoid allowing a solitary dolphin to develop into a solitary-sociable dolphin whenever possible.