Previous domestic studies on cross-border mergers and acquisitions (M&As) have generally agreed that the announcement of overseas acquisitions by Korean firms has a negative effect on acquiring firms' value (shareholder wealth). These results are contrary to those of prior studies centered on U.S. firms, and in Korea, cross-border acquisitions have been interpreted not as a strategy for pursuing excess returns through internationalization, but rather as a means of survival strategy to endure fierce domestic and international competition (the survival strategy hypothesis). However, prior domestic studies suffered from small sample sizes and samples distributed over relatively short periods, making it somewhat difficult to draw general conclusions. Moreover, a considerable number of samples classified as cross-border acquisitions in prior studies actually included greenfield investments, international joint ventures, or simple equity investments without acquisition of management control, suggesting problems in the sample selection process given the research objective of testing the announcement effects of cross-border acquisitions. In this study, we carefully analyzed a sufficient number of events over a comparatively long period of 19 years (1986–2004) to select our sample, then analyzed the effects of Korean firms' cross-border acquisition announcements on acquiring firms' value (announcement effects), and additionally conducted an exploratory analysis of the factors influencing these announcement effects (determinants of announcement effects). The results showed that, unlike prior studies, the acquiring firms' cumulative average abnormal returns (CAAR) consistently exhibited positive signs throughout the event period (although not statistically significant), indicating that investors do not perceive cross-border acquisitions by Korean firms as events that negatively affect acquiring firms' value. Meanwhile, in the analysis of determinants of announcement effects, cross-border acquisitions motivated by technology acquisition showed greater increases in firm value compared to acquisitions driven by other motives, suggesting that the reverse internalization hypothesis is an appropriate theory for explaining cross-border acquisitions by Korean firms. Additionally, acquisitions of firms in developing countries were found to decrease acquiring firms' value, and industry relatedness between acquiring and target firms did not affect acquiring firms' value, indicating that the multinational network hypothesis was not supported.