Two little-known nematode species of the family Camallanidae, intestinal parasites of marine perciform fishes, are reported from off New Caledonia: Procamallanus (Procamallanus) annulatus Yamaguti, 1955 from the golden-lined spinefoot Siganus lineatus (Valenciennes) (Siganidae) and Procamallanus (Spirocamallanus) monotaxis (Olsen, 1952) from the longspine emperor Lethrinus genivittatus Valenciennes and the slender emperor Lethrinus variegatus Valenciennes (both Lethrinidae). Detailed light and electron microscopical studies (the latter used for the first time in these species) revealed some taxonomically important, previously not observed features, such as the presence of deirids, six crescent-shaped elevations surrounding the mouth, three poorly developed protuberances on the female tail tip and circumcloacal papillae and phasmids on the male tail in P. annulatus, and the presence of a circumoral flange, only 12 (instead of 14 reported) cephalic papillae, the shape of deirids and similar numbers (14 - 17 and 14 - 15) of spiral ridges in the male and female buccal capsules in P. monotaxis. The fourth-stage larva of P. annulatus is described for the first time. First-stage larvae of both species were found to possess several digital processes at the tail tip. The present findings represent new host and geographical records of these parasite species.