Prior herpetological surveys in 1996 and 2000 identified 14 species of amphibians and 32 species of reptiles from the Sahamalaza Peninsula. This work increases the total number of amphibian and reptile species known from this area to 20 and 43 respectively. To maximise our chances of species detection, survey effort covered the entire wet season and part of the dry season, and utilised a combination of opportunistic searching, transect searching, pitfall trapping, and acoustic recording. We identified species through an integrative taxonomic approach, combining morphological, bioacoustic and molecular taxonomy. Together, this enabled the detection of cryptic and seasonally inactive species that were missed in the shorter prior surveys that relied on morphological identification alone. The taxonomic identification of amphibians utilised a fragment of the mitochondrial 16S rRNA gene; taxonomic identification of reptiles utilised a fragment of the mitochondrial COI gene, and when necessary, also mitochondrial fragments of the 16S rRNA ND1, ND2, ND4 genes. All sequences were deposited in Genbank and COI sequences were also deposited in the BOLD database to foster taxonomic identification of malagasy reptiles. We report two new taxa: a species of Boophis, since described as B. ankarafensis, and a candidate new species of microhylid (genus: Stumpffia). We document range expansions of Boophis tsilomaro, Cophyla berara, Blaesodactylus ambonihazo beyond their type localities. Along with significant range expansions across a range of taxa, including Blommersia sp. Ca05, Boophys brachychir, Brookesia minima, Ebenavia inunguis, Geckolepis humbloti, Madascincus stumpffi, Pelomedus subrufa and Phelsuma kochi. Forest in the peninsula is under extreme pressure from human exploitation. Unless unsustainable agricultural and pastoral practices encroaching on these habitats halt immediately, both forest and the species that occur there, several of which appear to be local endemics, may be irreversibly lost.