A total of 55 domestic cats (Felis catus f. domestica) and one wild (Bengal) cat (Prionaluirus bengalensis) from the Vientiane Province, central Laos, were examined for helminth parasites with emphasis given to potential human parasites. The following species were found (parasites infective to man marked with an asterisk): Opisthorchis viverrini, Haplorchis pumilio, H. taichui, H. yokogawai, Stellantchasmus falcatus (Digenea); Spirometra sp., Dipylidium caninum, Taenia taeniaeformis (Cestoda); Capillariidae gen. sp., Toxocara canis, T. cali, Ancylostoma ceylanicum, A. tubaeforme, Gnathostoma spinigerum, Physaloptera preputialis (Nematoda); and Oncicola sp. (Acanthocephala). This study demonstrated that examination of cats may provide useful data on the occurrence of helminths which are potential causative agents of human diseases.