The aim of this paper is to analyse the effect of financial development and banking competition on economic growth using both structural measures of competition (market concentration) and measures based on the new empirical industrial organization perspective (Panzar and Rosse`s test and the Lerner index). The evidence obtained in the period 1993-2003 for a sample of 53 sectors in 21 countries indicates that financial development and the exercise of bank market power promote economic growth. The latter result is consistent with the literature on relationship lending which argues that bank competition can have a negative effect on the availability of finance for companies that are informationally more opaque. The results cast doubt on the use of market concentration measures as indicators of competition