This study examines the PCAOB’s Division of Enforcement from 2005 to 2017, a time period when it expanded from a $5 million to a $22 million program area.  We find that a pronounced increase in disciplinary orders issued during the latter years of the sample period is attributable to serious audit deficiencies and misconduct by triennially inspected audit firms, non-U.S. audit firms, and firms auditing brokers and dealers.  We also find that more than two-thirds of the violations of PCAOB auditing standards described in these disciplinary orders pertain to failures in general audit principles and responsibilities, obtaining audit evidence, and review and communication.  Finally, we find that the PCAOB levies punitive sanctions on an overwhelming majority of audit personnel and audit firms cited in these disciplinary orders.  Overall, our results indicate that the PCAOB’s enforcement function has actively disciplined audit personnel and audit firms that breached their professional obligations.