The purpose of this paper is to investigate the certification and monitoring roles played by underwriters in IPO earnings management. Prior studies show that IPO issuers have incentives to employ opportunistic earnings management to enhance initial firm values. However, the certification role of underwriters has been largely overlooked. We argue that there is a negative relation between underwriter reputation and IPO earnings management. Moreover, we think that underwriters have strong incentives to continue providing monitoring to the firms they take public due to the lucrative business relationships. We thus hypothesize that there is a positive relation between underwriter reputation and post-IPO firm operating performance. Using a sample of 367 IPOs, we obtain results consistent with our hypotheses. We find that IPOs underwritten by lower-reputation underwriters have more initial discretionary accruals and higher initial firm values, indicating there is a significantly negative relation between IPO earnings management and underwriter reputation. We also find that the post-IPO operating performance of IPOs is significantly and positively related to underwriter reputation. For the robustness test, we consider the possibility that IPO earnings management and the choice of underwriters are endogenously determined. An instrumental variable two-stage least squares regression and a weighted least squares regression confirm the robustness of our results.