A total of 1,318 wild geckos were collected in Cambodia, Thailand and Vietnam (Hue and the Mekong Delta) from 2012 to 2015 to determine the prevalence of Salmonella Weltevreden. Those geckos belong to three species: common house gecko (Hemidactylus frenatus), flat-tailed house gecko (Hemidactylus platyurus) and four-clawed gecko (Gehyra mutilata). Of 1,318 gecko samples, 293 (22.2%) samples were positive for Salmonella in this study. The prevalence of Salmonella in geckos was 46.0% in Thailand, 17.3% in Cambodia and 16.3% in Vietnam. Among the Salmonella isolates, S. Weltevreden was the most predominant serovar (32.1%) isolated from wild geckos in these countries. There was no significant difference in the preva- lence of Salmonella among gecko species. All S. Weltevreden isolates (100%) were susceptible to the nine antibiotics examined in this study. The PFGE assay by XbaI enzyme identified 19 different patterns from 75 S. Weltevreden isolates. These isolates showed high genetic heterogenicity, and there were specific types prevalent in each region. Furthermore, S. Weltevreden has been prevalent since the ancient times in this region. The results indicate that wild gecko seems to be an important natural reservoir for S. Weltevreden as well as a source of Salmonella infections in humans in Southeast Asian countries.