We examine how information uncertainty surrounding IPO (initial public offering) firms influences earnings management and long-run stock performance. For low-information-uncertainty issuers, at-issue earnings' management is positively related to subsequent unmanaged earnings and has no relationship to market reaction to earnings announcement and long-run stock performance following the offering. For high-information-uncertainty issuers, however, at-issue earnings' management is unrelated to subsequent unmanaged earnings and negatively related to market reaction to earnings announcement and long-run stock performance following the offer. The evidence suggests that, on average, managers in low-information-uncertainty firms tend to engage in earnings' management for informative purposes, while managers in high-information-uncertainty firms engage in earnings' management for opportunistic purposes.