This paper examines the effect of control changes on efficiency and productivity in the banking industry of Argentina. This industry represents an interesting case study as banks underwent corporate changes of different types including privatization, foreign acquisition of domestic banks and mergers and acquisitions among local institutions. Bank productivity is measured and decomposed into the effects due to returns to scale, technical progress and efficiency, while bank efficiency is related to a set of variables controlling for changes in bank ownership. The evidence suggests that control changes due to privatization had a positive short‐term effect on productivity in part as a result of efficiency gains, which were then gradually lost over time. Results also indicate that foreign acquisitions led to stronger productivity performance of acquired banks, though they did not have any significant effect on efficiency. Finally, mergers and acquisitions had a negative impact on productivity as a result of scale effects despite the long‐term efficiency improvements.