We present the first herpetological checklist for the Kulen Promtep Wildlife Sanctuary in northern Cambodia, with records of 22 species of amphibians and 33 species of reptiles belonging to 44 genera in 22 families. The checklist includes three species (Ingerophrynus macrotis, Micryletta inornata, Scincella melanosticta) which in Cambodia were formerly only known to occur in the Cardamom Mountains in the southwest of the country. Our findings highlight the importance of countrywide herpetological baseline surveys in lowland habitats.