[Objectives]  To quantify sexual wing dimorphism in Pantala flavescent Fabricius. [Methods]  We obtained wing shape information by digitizing the fore and hindwings of P. flavescens. Sexual dimorphism in wing shape and vein structure was then analyzed by principal component analysis (PCA) and the thin-plate spline (TPS) graphical technique. [Results]  The PCA results indicate significant sexual dimorphism in the fore and hindwing. TPS indicates that forewing differences are mainly in the nodus and triangle, whereas hindwing differences were mainly in the nodus and in the area of the cubital and anal veins. Centriod size (CS) indicates that females have a bigger fore and hindwing than males. [Conclusion]  Sexual dimorphism in wing shape in P. flavescens probably reflects selection for different wing shape and vein structure in each sex.