This contemporary study addresses the mergers and acquisitions (M&A) and provides insight to the impacts of M&A. It explores the effects of merger on profitability of the bank by using six different financial ratios. We have selected 10 commercial banks that faced M&A during the period from 1999 to 2010. The lists of banks were selected from the Karachi Stock Exchange (KSE). Quantitative data analysis techniques are used for inference. Data were collected from the annual reports of the sample banks for the period of six years (three years before the combination and three after). Analysis was done by using paired t-test. Study concluded that our all alternate hypothesis are rejected because. The results recommend that operating financial performance of all commercial bank’s M&A included in the sample from banking industry had declined later. The results shows that there is a decline in all 6 ratios: profitability ratios, return on net worth ratios, invested capital, and debt to equity ratios. We can argue that increased performance after M&A is not necessary and it varies with contextual factors.