This article examines the long-run stock market performance of German and Spanish initial public offerings (IPOs) between 1990 and 2000. We distinguish between family- and nonfamily-owned business IPOs by using the power subscale of the F-PEC. Buy-and-hold-abnormal returns (BHAR) are calculated in order to determine abnormal returns. Our results show that three years after going public, investors, on average, realized an abnormal return of −32.8% for German and −36.7% for Spanish IPOs. In both countries, nonfamily business IPOs perform insignificantly better. Regression analyses show that for the whole sample there is a positive company size effect. In family-owned businesses, strong family involvement has a positive impact on the long-run stock market performance, whereas the age of the firm has a negative influence.