The objective of this study is to present the evolution of the financing of Greek enterprises during the years of crisis, and in particular analyze the impact of the crisis on companies' access to external financing. The deep economic crisis that hit Greece is reflected, inter alia, in the main macroeconomic ratios, like Gross Domestic Product and unemployment and some indicators of the banking sector, like deposits, total loans and non-performing loans. Greece is characterizes today by borrowing problems, high public debt, serious lack of competitiveness, unsustainable social security system, particularly poor public administration and a large and wasteful public sector. Economic crisis decreased firms' profitability and increased their needs for external sources of financing. In the situation when internal sources are limited external capital is the main source allowing to finance firm's investment projects. Insufficient availability of external capital can restrict future firm's growth opportunities and its competitiveness. In this paper we analyze two main sides of the problem of business financing: the supply and demand of external capital. The extreme reluctance of banks to lend Greek companies because of the strict financing constrains due to the national debt crisis exacerbates the cycle of economic recession and seriously undermines the efforts of Greek companies to continue their activities. In new circumstances banks try to limit risk. But in the current environment they have trouble finding creditworthy borrowers. As a result the credit market is very constrained. On the other side economic crisis decreased firms' profitability and increased needs in finding ways to gain funds. The analysis shows that small and medium enterprises have been particularly affected by tighter credit conditions and financial instability. Debt financing has become more expensive and difficult to obtain.