The paper presents theoretical aspects of the relationship between financial market development and economic growth, and its effect in the Euro-12 area in the years 1991–2008. The first part of the paper also outlines results of selected empirical research of the influence of financial market development on economic growth. A multi-equation econometric model estimated by means of a classical method of least squares was usedand cointegration tests were also carried out. An analysis of interdependencies between the two selected indicators shows that there is a statistically significant relationship between the financial market development and economic growth in the Euro-12 area in the examined period.