We describe a new species of forest frog (genus Platymantis) from Mt. Malinao, Bicol Peninsula, southern Luzon Island, The Philippines. The new species is distinguished from congeners by a moderate body size (28.3–39.1 mm for eight males; 49.8–52.7 in two females), slightly expanded terminal finger and toe disks, a distinct color pattern, a unique microhabitat preference, and various spectral and temporal aspects of the advertisement call. The new species is known only from 950–1160 m above sea level on Mt. Malinao and, as such, accentuates this mountain's unrecognized conservation significance as a minor center of herpetological diversity and endemism on southern Luzon. We compare the new species to all presumably related (phenotypically similar) species of Platymantis from the Philippines and comment on apparent trends in morphological evolution and habitat preference in Philippine members of the genus Platymantis. Current understanding of Platymantis species diversity throughout this topographically and geographically complex archipelago is underestimated and in need of comprehensive review.