The first mass stranding of Risso's dolphins Grampus griseus on the Peruvian coast occurred on Pozo de Lizas Beach (17°42′30.3″S 71°18′48.7″W), port of Ilo, Department of Moquegua, southern Peru, between 7 and 8 June 2007. At least 14 Risso's dolphins were stranded along 1.5 km of beach. Just 7 of them could be sized and 8 sexed; this group was composed of 7 males and a single female plus a juvenile of undetermined sex. Mean standard body length of the males was 299.67 cm (SD: 9.91 cm, range: 292–317 cm) and the female measured 289 cm. The entire group, including four individuals found alive, was illegally butchered by the local people to use the meat as food, while other remains were used as bait in the pelagic long-line fishery. This record fills a distributional gap of about 1000 km in the known distribution of the species between central Peru and northern Chile. Additional education is required for improved conservation strategies in future cetacean strandings.