In this paper we examine the risk-adjusted profitability of merger arbitrage in Australia. Using a sample of 193 merger and acquisition bids from January 1991 to April 2000, we construct a time series of returns on equal and value-weighted merger arbitrage portfolios. Benchmarking the returns on the merger arbitrage portfolios against the CAPM and Fama and French (1993) three-factor models, we find that merger arbitrage generates statistically and economically significant excess risk-adjusted returns before transaction costs, ranging from 0.84% to 1.20% per month. However, after adjusting for transaction costs, the risk-adjusted returns are no longer statistically significant. Further, in contrast to the United States, our evidence indicates that merger arbitrage in Australia is a market-neutral investment strategy. Indeed, the results from our estimations of the linear CAPM and Fama and French (1993) three-factor models suggest that merger arbitrage returns are not significantly sensitive to market-wide factors.