This study examined the announcement effects for acquirers from the years 2000 to 2013. Since acquisitions create agency problems and companies in Malaysia exhibit concentrated ownership structures, this study aimed to investigate three major objectives namely the effects of family control, blockholder activism, and board structures on the stock performance of acquirers. In addressing these objectives, the three-day abnormal returns one day before the announcements were adopted as the proxy for the announcement effects. Ordinary least squares regression methods were used to examine the effects of the 10 factors on abnormal returns. The results show that acquisitions in Malaysia were value-enhancing, which is consistent with the synergistic theory. Family ownership and active institutional blockholders were able to create value which implies that family-controlled firms do not engage in opportunistic behavior. Moreover, institutional blockholders should play an active role if they want to protect their investments. The study has implications on regulators such as the Securities Commission (SC) with regards to board composition in which independent directors should consist of at least one-third of it because such composition leads to more significant values.