Abstract: We analyse potential sources of internal imbalances, specifically as regards private and public indebtedness. The combination of a high public debt and increasing private sector indebtedness have been a source of concern in the perspective of the funding of the economy in examined countries. We utilize the detailed financial accounts as an analytical framework for revealing the development of private sector 's indebtedness in 18 EU countries in the period 1995-2012. Ratio of private debt (non-financial corporations, households and non-profit institutions serving households) to GDP was steadily increasing till 2009 with a decrease in the following years. After the decomposition of the private sector debt several facts stand out. Highly indebted, on the average, are households in Denmark and The Netherlands. Postsocialist countries have still low indebtedness, but are catching up. In panel regressions (fixed effects) the dependent variable is overlapping two-and free-year forward looking averages. The control variables are those usually used in growth equations a la R. Barro. We have utilised also instrumental variables (Pooled IV Two-stage EGLS) and 3 years averages for all variables to capture medium-run impacts. Having analysed the impacts of different private debt variables on the growth rate of real GDP we assert that the impact has been negative and statistically significant in almost all growth regressions.