Adults of 2 new species in 2 orders of acanthocephalans obtained from the intestines of terrestrial amphibians and reptiles collected between 1998 and 2004 in Vietnam are described here. Pseudoacanthocephalus nguyenthileae n. sp. (Palaeacnthocephala: Echinorhynchidae) was collected from 5 species of terrestrial amphibians: (1) the common Sunda toad Bufo melanostictus Schneider (Bufonidae); (2) Paa verucospinosa (Bourret); (3) Gunther's Amoy frog Rana guentheri Boulenger; (4) Taipei frog R. taipehensis Denburgh (Ranidae), and (5) the Burmese whipping frog Polypedates mutus (Smith) (Racophoridae); as well as from the Chinese cobra Naja atra Cantor (Reptilia: Elapidae) and house gecko Hemidactylus frenatus Dumeril and Bibron (Reptilia: Gekkonidae). Sphaerechinorhynchus maximesospinus n. sp. (Plagiorhynchidae: Sphaerechinorhynchinae) was isolated from a king cobra Ophiophagus hannah (cantor) (Reptilia: Elapidae). Cystacanths of Porrorchis houdemeri (Joyeux and Baer, 1935) Schmidt and Kuntz, 1967 (Plagiorhynchidae: Porrorchinae) obtained from the mesenteries of banded krait Bungarus fasciatus (Schneider) (Reptilia: Elapidae), a paratenic host, are reported for the first time. Keys to the species of Pseudoacanthocephalus and Sphaerechinorhynchus are included. Characteristic features distinguishing the new species from related taxa include: P. nguyenthileae has 15–19 (usually 16–18) proboscis hook rows, each with 5–6 hooks that progressively increase in length and size posteriorly. The largest, intermediate, and smallest proboscis hooks of S. maximesospinus are the middle, anterior, and posterior hooks, respectively; the proboscis and neck are enclosed in a membrane. Morphometric characteristics of P. nguyenthileae show host-related variability.