In this paper we develop various measures of M&A failure for an intra-European sample during the fifth takeover wave: inferior long-term stock performance, inferior operating performance, and target divestment. After documenting the extent of M&A failure, we test the relation between short-term abnormal returns at deal announcement and M&A failure. We examine a sample where listed bidders acquire listed targets (267 deals) as well as privately-held targets (336 deals). Our results indicate M&A failure rates up to 50% in both samples. When acquirers and targets are listed, lower M&A announcement returns are consistently and significantly associated with higher M&A failure probabilities and long-term losses. In contrast, when targets are privately held, we find no evidence of such an association.