This paper examines the impact of bank competition on firms' access to credit using a large panel of 900 banks matched to almost 60.000 firms across the euro area over the period 2010- 2016. Results provide empirical support for the market power hypothesis whereby low inter- bank competition worsens firms' credit conditions. We find that higher bank market power is associated with lower short and long-term bank credit, higher reliance on trade credit and higher funding costs for customer firms. Furthermore, high bank market power is especially detrimental for opaque firms, suggesting that lower inter-bank competition exacerbates the financial constraint ofborrowers that are more exposed to information problems. By contrast, we find limited evidence consistent with the information hypothesis: among firms related to banks with high market power, those served by small banks are less credit constrained than those served by large banks.