Mergers and Acquisitions (M&As) are the vital growth strategies of corporates in the scenario of globalization and liberalization to face competition and move ahead. M&A have grown not only in volume but also in value. It is often stated that the companies go for inorganic growth strategies like M&A to improve performance. There is no clear-cut support from the literature about the effect of M&A on corporate performance. As per various studies, companies perform either better or worse after M&As. But the question arises how long the effect of mergers and acquisitions remain on the companies. The present study is an attempt to find out the time frame for knowing the effects on performance of manufacturing companies from M&A. The results suggest that the impact of M&A on companies are reflected in the immediate years specifically the event year and the post M&A one year.