H. obscurus is dependent on primary and disturbed lowland forest (Heaney et al. 2006). It is generally a cave-roosting species although an individual has been recorded roosting in a mine shaft, one in a dark cavity in a tree buttress (Heaney et al. 1991, Taylor 1934), and another in a hollow tree (Sanborn 1952, Heaney et al. 1998, L. Heaney pers. comm. 2006).

The Philippine forest leaf-nosed bat is endemic to the Philippines. There are records from the islands of Bohol, Catanduanes, Cebu, Dinagat, Luzon (Benguet, Camarines Sur, Isabela, Laguna, Pampanga, and Tarlac provinces, though it probably occurs through the island (L. Heaney pers. comm.)), Leyte (Leyte and Southern Leyte provinces), Occidental and Oriental Mindoro, Maripipi, Mindanao (Bukidnon, and South Cotabato provinces), Mindoro (Oriental Mindoro province), Negros (Negros Occidental and Negros Oriental provinces), Pollilo, Siquijor (Heaney et al. 1998). However, on Mindanao it has recently been more widely: a) in lowland forest on Mount Hamiguitan (Mati, Davao Oriental); b) lowland forest at Cantilan and Carrascal on Mount Hilong-hilong (Surigao del Sur); and c) montane forest on Mount Hilong-hilong (Agusan del Sur) (Gomez in litt. 2007). It is usually found from sea level to 850 m asl (Heaney et al. 1998) and up to 1,100 m asl on Mount Katanglad (Mindanao) (Heaney et al. 2006).

H. obscurus occurs in a number of protected areas.