The aim of this study was to elucidate zygomatico-facial foramen (ZFF) relating to malar reduction surgery. Fifty-five dry skulls of adult Koreans were studied. A total of 100 (90.9%) ZFF were observed in 110 skulls. ZFF was variably more than one: one in 56 specimens (50.9%), 2 in 33 (30%), 3 in 10 (9%), and 4 in one (0.9%). ZFF was located 7.3 mm lateral and 3.7 mm inferior to P point, which was defined as crossing a line along the upper border of the zygomatic arch and a vertical line on the lateral orbital rim. The distance from the zygomatic suture to ZFF was 24.4 mm on average. ZFF was located 7.61 mm from the closest orbital rim. ZFF was located 13.0 mm from the nearest zygomatic angle (the junction of the zygomatic arch and lateral orbital rim). Most ZFF were within an ellipse of 15 mm in the major axis and 5 mm in the minor axis. The ellipse was 5 mm from P point. Our data suggest the osteotomy line in malar reduction should be placed at least 10 mm lateral to the lateral orbital rim.