Three new species of free-living nematodes of the family Leptolaimidae from the Cam River, Vietnam are described and illustrated. Antomicron intermedius sp. n. is close to A. elegans (de Man 1922) and A. pratense Lorenzen 1966. This species differs from the former in the shorter body, shorter stoma, shorter cephalic setae, shorter spicules, and the greater number of tuber supplements in males. It differs from the latter in the longer body, vulva location closer to the front body edge, the presence of cephalic setae, and the greater number of tuber and alveolar supplements. Leptolaimus vipriensis sp. n. differs from the related species L. gerlachi Murphy 1966 in the longer cephalic setae, the absence of stomatic setae, more in front location of amphidial fovea, different shape of gubernaculum, and the absence of terminal setae in male tail. Leptolaimoides asiaticus sp. n. differs from L. tubulosus Vitiello 1977 in the shorter body, longer stoma, and longer spicules.