The aim of this paper is to determine the impact of structure of debt funding sources on liquidity of medium-sized companies in the Czech Republic from 2006 to 2015. With the purpose to fulfill the aim, we determine the impact of structure of debt funding sources including variables such as debt equity ratio, supplier loans, long-term bank loans, short-term bank loans, other long-term liabilities, other short-term liabilities on liquidity of medium-sized companies in the Czech Republic. The relationship between structure of debt funding sources and liquidity of medium-sized companies is determined using a correlation analysis and panel regression analysis using generalized method of moments (GMM). The results confirm that there is negative impact of long-term bank loans on liquidity of medium-sized companies in the Czech Republic. The results also confirm the positive impact of other short-term liabilities on liquidity of medium-sized companies in the Czech Republic.