The vascular anatomy of submental flaps (SFs) represents a determining factor in successful SF raising. However, little attention has been focused on the venous return of SFs. Thus, the present study aimed to investigate SF venous return. This study enrolled patients who underwent SF reconstructive surgery in a tertiary referral center between November 2009 and October 2016. The drainage pathway of the SF venous return was routinely identified during the course of our operations to prevent damage during head and neck surgery. The venous return data of 70 patients were reviewed. The size of the flaps ranged from 15 to 84 cm2, and total flap loss was not observed in the case series. All of the submental arteries originated from the facial artery; however, the submental veins of 70 patients returned to either the internal jugular vein (IJV, 72.9%) or the external jugular vein (EJV, 27.1%). Our data suggest that drainage of the submental vein into the EJV, which has been previously overlooked, should receive greater attention during SF surgeries. The results support mandatory preservation of the EJV and IJV and indicate that vascular anatomy is a determining factor for successful SF raising.