Euphausiids have been well studied in several regions of the Pacific Ocean; however, there is lessinformation regarding euphausiids in Costa Rican waters. We analyzed euphausiid specimens collected aroundIsla del Coco National Park during 2011 and 2012. A total of 130 specimens were analyzed and 13 euphausiidspecies were identified, belonging to four genera and one family. An annotated list of species is presented,with photographs and details for their identification. All species found represent new records for waters aroundIsla del Coco in the Costa Rican Pacific. The most frequent species were Euphausia diomedeae, Euphausiadistinguenda, Nematoscelis gracilis and Stylocheiron affine. Rev. Biol. Trop. 64 (Suppl. 1): S221-S230. Epub2016 Febrary 01.