This paper studies the effects of the interfacial friction distribution on the integrity of superplastic formed parts. For that purpose, the deformation of an AA5083 superplastic aluminum alloy into a long rectangular box is investigated. The die surface is divided into five regions for local application of constant friction coefficients. The commercial finite element code (Abaqus) is used to carry out the forming simulations and calculate the thickness distribution, forming time and forming pressure profile for different combinations of friction coefficients. It was found that the friction distribution at the die-sheet interface strongly affects the metal flow during the forming process. This is a key factor that can be controlled and optimized so as to enhance parts integrity and prevent localized thinning.