We study the mergers of US publicly traded bank holding companies during 1987–2000 and find that the acquiring firm's sustainable growth rate is an important determinant of the cross‐sectional variation in the merged entity's long‐term operating and stock performance. The most economically significant determinants of the merged bank's abnormal stock return performance are the acquiring bank's estimated sustainable growth rate prior to the acquisition, as well as post‐acquisition changes in this growth rate, and the bank's dividend payout ratio. Our findings are robust even after controlling for several potentially confounding factors.