This study examines the returns to 2340 merger deals conducted by frequent acquirers in 17 emerging markets, during the period to June 2008. Our primary findings are as follows. Serial acquirers in emerging countries on average experience a declining pattern in returns with subsequent deals, but the pattern is no strong. However, conditional on successful initial deals, the declining pattern is strong for the majority of countries, is large in terms of the magnitude, and is significant in the multivariate regression analysis. We interpret the results as somewhat supportive of the hubris behavior as a factor in serial acquisitions (Roll, J Business 59, 1986). We also find a stronger declining pattern for more developed markets but no substantial difference between civil and common-law countries; the former might be explained by generally greater and increasing competition for control in more developed markets