Twenty species of Pectinoidea (12 Propeamussiidae, three Cyclochlamydidae, five Pectinidae) are herein listed. Six new species of Pectinoidea (three Propeamussiidae, three Cyclochlamydidae) are from littoral and bathyal depths of the western and southwestern Pacific, sampled by various expeditions and cruises to Papua New Guinea and the South China Sea, viz. Propeamussium regillum n. sp. from the bathyal Bismarck and Solomon Seas, Parvamussium minusculum n. sp. from the lower bathyal South China Sea, Cyclopecten inoculatus n. sp. from the bathyal Bismarck Sea, Cyclochlamys corrugata n. sp., Cyclochlamys barbatula n. sp. and Micropecten reticulatus n. sp. from shallow coastal waters of Papua New Guinea. Fourteen species of Pectinoidea (nine Propeamussiidae, five Pectinidae) are new records for the Bismarck Sea (five), for the Solomon Sea (four), and for the South China Sea (seven).