We analyze the determinants of the corporate interest rates and the financial accelerator in the Czech Republic. Using a unique panel of 448 Czech firms from 1996 to 2002, we find that selected balance sheet indicators influence significantly the firm-specific interest rates. In particular, debt structure and cash flow have significant effects on interest rates, while indicators on collateral play no significant role. We find evidence that monetary policy has stronger effects on smaller firms than on medium and larger firms. Finally, we find no asymmetric effects in the monetary policy over the business cycle.