International diversification is now an established fact for stock and bond portfolios. For real estate shares, however, this acceptance has so far not been the case. This study is an investigation of the effectiveness of international real estate diversification relative to international diversification of stock and bond portfolios. Tests of international correlation matrixes of real estate returns, common stock returns, and bond returns indicate significantly lower correlations between national real estate returns than between common stock or bond returns. The implication is that international diversification reduces the risk of a real estate portfolio more than that of common stock and bond portfolios.