Abstract This study investigates how investor sentiment affects the cross-section of stock returns in Taiwan stock market. The main hypotheses are investor sentiment has effects on securities whose valuations are subjective and difficult to arbitrage. We find that when beginning-of-period proxies for sentiment are low, subsequent returns are relatively high for unprofitable stocks, non-dividend-paying stocks. However, when sentiment is high, these categories of stock earn relatively low subsequent returns. Keywords: investor sentiment, the cross-section of stock returns, Taiwan stock market.