Samples of small flying fox were collected from Bababu Dinagat Islands and Hundred Islands Pangasinan and were subjected to gross morphology and histological evaluation. Gross anatomy evaluation revealed that the heart of small flying fox is oval in shape with the base of the heart being wider than the apex and surrounded by pericardium that appears as a transparent and firm structure. Fats and lymphatic tissue are also found around the heart and its blood vessels. The heart has a mean weight of 4.7 ± 0.42 grams for male and 4.7 ± 1.92 grams for female. Its left and right atrial wall showed no difference in their thickness and has a smooth wall while the left ventricular wall is twice the thickness of the right ventricular wall. The heart samples have two papillary muscles on the right and left ventricle. The number of chordae tendinae on the left ventricle is 5 while it has four chordae tendinae on the right ventricle. Female small flying fox right lung have a mean length of 5.4 ± 1.47 cm, mean width of 6.47 ± 0.47 cm and mean weight of 6.83 ± 1.90 grams. The male small flying fox right lung has a mean length of 5.50 ± 0.14 cm, mean width of 6.45 ± 0.35 cm and mean weight of 6.85 ± 0.07 grams. The female small flying fox left lung has a mean length of 5.17 ± 0.90 cm, mean width of 5.17 ± 0.61 cm and mean weight of 5.0 ± 0.96 grams. The male small flying fox left lung has a mean length of 5.15 ± 0.35 cm, mean width of 5.15 ± 0.64 cm and mean weight of 5.0 ± 0.28 grams. Similar with other mammals or bats, the primary bronchi are lined with pseudostratified columnar epithelium, the secondary bronchi lined with columnar ep- ithelium and the tertiary bronchi have a cuboidal lining epithelium. The bronchioles are lined with simple cuboidal epithelium while the alveoli are lined with simple squamous epithelium. Type I and Type II pneumocytes were also observed.