Niassa Special Reserve in northern Mozambique is the country's largest protected area yet remains remarkably biologically understudied. From 2016 to 2021 we conducted a series of herpetofaunal surveys using pitfall traps and visual encounter surveys and recorded a total of 34 amphibian and 58 reptile species. Of these, 10 amphibian and 10 reptile species were new records for the reserve, substantially increasing the area's known species diversity to 39 amphibian and 66 reptile species respectively. We prioritised wet-season data collection and important discoveries included a first country record of Nucras boulengeri (Lacertidae), a significant range extension for Breviceps poweri (Brevicipitidae) and observations of Hemisus guineensis (Hemisotidae) and Tomopterna adiastola (Pyxicephalidae) that fill broad gaps in these species' known distributions. Here, we present biological and conservation remarks for notable species along with updated reptile and amphibian species lists for Niassa Special Reserve.