This presentation will comparatively analyze the historical process of the invention and development of the laminar flow airfoil in prewar Japan and the United States. Itiro Tani, the Japanese aeronautical engineer at Tokyo Imperial University, studied boundary layer and based on its aerodynamic research, proposed the design of the laminar flow airfoil. The American engineer Eastman Jacobs at NACA also designed the laminar flow airfoil, a few months prior to the Japanese design. Both of them relied on the idea proposed by the British engineer B. Melvill Jones on the possibility of retarding the transition point from laminar to turbulent boundary layer over the wing surfaces. After knowing the results of Jones’s investigation, American and Japanese engineers independently took similar paths of the development of the new airfoil. They diverged, however, in the subsequent manufacturing process of producing wings: While the Americans successfully manufactured precisely shaped and polished wings, the Japanese had difficulty in manufacturing such wings. I will show and discuss these historical processes of the invention, development, and construction of the laminar flow airfoil in both countries.