Debt financing decision is the most important and crucial decision in the study of capital structure and financial structure because it leads to firm s performance. The current Study empirically investigated a number of factors affecting debt financing decision and firm s performance for the non-financial companies listed in Karachi Stock Exchange of Pakistan for the period of 2005-2010. The financial theories like Tradeoff theory (TOT) and Packing order theory (POT) has also been tested in order to see the consistency of factors affecting the debt financing behavior in the current study with above said theories. A Panel data of 341 firms has been used for empirical analysis of the current Study. The variation in debt financing is measured by short-term, long term and total debt while the variation in firm s performance is measured by profitability and Return on Assets. The current study empirically examined the effect of firm s specific factors by econometric practice one way-fixed effect regression model . The Current study will help the reader for understanding how the different factors affects debt financing and firm performance in non-financial sector of Pakistan