The genus Cryptolaemus Mulsant endemic to New Guinea / Australasia is reviewed. Thirty-two new species (C. tetrahedron, C. simulatus, C. sigmoidus, C. distinctus, C. pulchellus, C. dualis, C. ambiguus, C. sedlaceki, C. iodes, C. purpureus, C. parvus, C. prominens, C. metallicus, C. magnificus, C. splendidus, C. regalis, C. splendens, C. riedeli, C. dubius, C. trochanteratus, C. similis, C. aeruginosus, C. bicolor, C. asymmetricus, C. incertus, C. typicus, C. incrassatus, C. robustus, C. fraternus, C. atratus, C. guineensis, C. gressitti, spp. nov.) are described and illustrated. Cryptolaemus concinnus Weise is redescribed and the male genitalia are illustrated. Besides montrouzieri-group and subviolaceus-group, four more species groups are tentatively recognized based on male genitalia and other characters: iodes-group, magnificus-group, riedeli-group, and bicolor-group, and some of the species are unassociated with any of these groups. A key is provided to the males of the species of Cryptolaemus from New Guinea, mainly based on genitalia. Presence of a stridulatory apparatus is reported from species of the riedeli-group, which is the first of its kind in Coccinellidae.