The goal of this paper is to investigate the impact of contextual variables on Management accounting system design in Egyptian hospitals which suffer complexity and continuous inept administration despite years following its reform in 1994. Based on the Management accounting system dimensions (scope, timeliness, aggregation, and integration) defined by Chenhall and Morris (1986), a contingency-basedintervening model is proposed whereby the extent of use of Management accounting system plays a significant intervening role between organizational strategy, technology, organizational structure, external environment, and hospital size, on managerial performance. It is expected that the direct relationships between the antecedent variables and managerial performance will be minimal, if not insignificant, when using Management accounting system as a mediating variable.