This dataset, belonging as a whole to Tethys Research Institute, comprises the work carried out between 1986 and 2012 mainly in the Mediterranean Sea and in particular in the Corso-Ligurian-Provencal basin, in the Ionian Sea and in the Adriatic Sea. Research has also been carried out investigating cetaceans in Atlantic Ocean (Canary Islands, Morocco coasts) and in the Caribbean Sea. The dataset generated includes more than 8.400 sightings of cetaceans collected in 25 years of research activity.