In 2005 and 2007, we conducted surveys of mammals along an elevational transect on Mount Palali (peak 1707 m) in the Caraballo Mountains, a poorly known mountain range on Luzon Island, Philippines. The surveys covered eight localities representing habitats from lowland agroforest and regenerating disturbed lowland rainforest at 780 m to mossy forest near the peak. We recorded 24 species, including one native shrew, one non-native shrew, five fruit bats, seven insectivorous bats, one monkey, six native rodents, two civets, and one pig. One species of Apomys is the newly described A. sierrae, and two species of Chrotomys are potentially undescribed species. Elevational patterns varied among mammals: bats were most diverse in the lowlands, native nonvolant small mammals had almost equal richness along the entire elevational transect, and most species of large mammals were present at all elevations. Bait attractiveness and diel activity pattern differed among native nonvolant small mammals: Apomys microdon and Rattus everetti were nocturnal and attracted to coconut baits, Chrotomys sp. 1 and 2 were mostly nocturnal and favored earthworms, Crocidura grayi showed no bait preference and was active during day and night, and A. sierrae showed no bait preference and was most active at night. The non-native Suncus murinus was restricted to highly disturbed areas at 780 m, whereas all native nonvolant small mammals were present in both degraded and undisturbed forest, supporting the hypothesis that non-native small mammals are not successful in invading native habitats on oceanic islands when the native community of small mammals is diverse. We conclude that all three rainforest types at all elevations, including newly regenerating forest, provide important habitat for mammals on Mount Palali.