Three new species, Hyalopecten vityazi sp. nov., H. abyssalis sp. nov. and H. kurilensis sp. nov., are described from the abyssal and hadal zones of the North-western Pacific. Hyalopecten vityazi was found in the Kuril-Kamchatka and Aleutian trenches at 6090–8100 m depth. It is the most deep-water species of the order Pectinida. Hyalopecten abyssalis and H. kurilensis were found at the abyssal plain adjacent to the Kuril-Kamchatka and Aleutian trenches at 4550–5045 m depth. To date, 13 species of the genus Hyalopecten are known from different regions of the World Ocean. A table with the main differences among all known species in the genus is provided.
