This paper shows the effect of top management (TM) and board of directors (independent variables) on firm's performance (dependent variable) applied on Egyptian listed companies. The composition of both TM and board of directors are investigated through the study of culture, age, tenure and gender diversity in board and TM.                                      The developed hypotheses are tested on Egyptian listed companies. Full Data have been collected from the financial statements in the annual reports of 197 companies for the year 2018 from all Egyptian companies listed on the Egyptian Stock Exchange. The results show that: first, for board of director's part, it is only the diversity of tenure that has a positive effect on performance, while cultural and gender heterogeneity has a negative effect, and age diversity shows no performance effects. Second, for TM part of the study indicates no effects of cultural, age and tenure diversity on firm performance while showing a positive effect of woman top managers' representation on firm performance.