Current advice on the design of dorsal tongue flaps is conflicting because of insufficient understanding of the blood supply. A detailed study of the vascular anatomy shows that the dorsal mucosa has a distinctive vascular pattern that commends the choice of a posteriorly-based midline flap for closure of defects in the soft palate and posterior part of the hard palate. More anterior defects are more easily closed with an anteriorly-based midline flap.