Species composition and microhabitats of frogs in the Arakan Valley Conservation Area in Cotabato, Mindanao, with three interconnected mountain ranges, were documanted using belt transect sampling. Frogs were sampled at 4 sites - one on Mt. Mahuson, two on Mt. Sinaka and one within the Kabalantian-Binoongan mountain range. Twenty-five frog species in 15 genera repesenting 5 families (Bufonidae, Megophyridae, Microhylidae, Ranidae and Rhacophoridae) were recorded, 9 of which are reported to be vulnerable. Fourteen species in 4 families were Philippine endemics, 9 of which are restricted to the Mindanao faunal region. Most species were encountered on ground microhabitats although majority of the individuals were seen on arboreal microhabitats. Overlaps in microhabitat use were also observed. Further, 56 % of the species were observed on forest edges. The high percentage of endimism may strengthen the importance of the site for conservation and the observed existence of species near edges might also highlight the conservation of all types of habitat.