Does market power of banks affect firm performance? To answer this question we examine 25,236 syndicated loan facilities granted between 2000 and 2010 by 296 banks to 9,029 US non-financial firms. Accounting for both observed and unobserved bank and firm heterogeneity, we find that firms that were recently poorly performing obtain loans from banks with more market power. However, in the year after loan origination market power positively affects firm performance, but only if it is not too high. Our estimates thus suggest that bank market power can facilitate access to credit by poorly-performing firms, yet at the same time also boosts the performance of the firms that obtain credit.