This study examines the impact of firm size, financial market development, liquidity and leverage on financial performance of selected non-financial Pakistani firms. For this purpose, data for the period of 2005-2014 of 100 non -financial companies listed in the Pakistan Stock Exchange have been used. Return on assets is used to measure firm performance as the dependent variable whereas the independent variables such as M2/GDP ratio are used as a proxy of financial market development, firm size is used by taking natural log of total sales, current ratio for liquidity and financial D/E ratio used for leverage. For empirical results we have used fixed effect and random effect models as estimation techniques. It has been found that out of the selected independent variables only financial market development and firm size have positive and significant relationship with firm’s performance. These findings have significant implications for company managers in increasing company’s profitability. Supervisor:- Ms. Farhat Mehmood