Poly (methylmethacrylate) has been established as principal material in denture base construction due to its good overall processing as well as user friendly properties. Nevertheless it is generally recognized that despite fulfilling aesthetic requirements, the impact and fracture strength of poly (methylmethacrylate) are not entirely satisfactory and this is reflected by the expenditure on a large number of denture repairs annually. The Objective of the study was to compare the fracture resistance of palatal denture bases made from two commercially available heat polymerized acrylic resin denture base material in different palatal vault configurations and in this study we finally Concluded that there is a direct relationship between the strength of the denture base and the palatal vault configuration. The shallow palatal vault base is inherently weaker and less resistant to fracture than medium and deep palatal vault. It's recommended to use a reinforced PMMA denture base or metallic denture base in shallow palatal vault.