This research aims to study and test the relationship between firm size and the firm's financial performance in an Egyptian floating environment, which is studied by testing effect of a macroeconomic variable which is exchange rate floatation, that took place in Egypt in November 2016, October 2022 and January 2023 on the firm's financial performance. These relations were tested in the presence of three control variables that are determinants of the firm's financial performance. These control variables are firm liquidity, firm loss and firm leverage.        The study was conducted on 319 firm-year observations of non-financial manufacturing firms listed on the Egyptian Stock Exchange (EGX) during the period 2015 – 2023. These firm-year observations encompass observations that took place in the years of floating exchange rate and others in the years of fixed exchange rate        The results of the empirical study concerning the first hypothesis indicated that there is a positive and significant effect of the firm size on the firm's financial performance in the presence of control variables. And the research results of the empirical study concerning the second hypothesis indicated that there is a positive direction, insignificant effect of the exchange rate floatation on the firm's financial performance in the presence of control variables.