Section 206 of the Investment Advisers Act of 1940 establishes a federal fiduciary standard under which an investment adviser has a duty to seek to obtain “best execution” of client transactions, taking into consideration the circumstances of the particular transaction. In other words, an adviser must execute securities transactions for clients in such a manner that the client’s total costs or proceeds in each transaction are the most favorable under the circumstances. Ensuring best execution, however, is challenging given the highly subjective nature of the assessment. The SEC Office of Compliance Inspections and Examinations (OCIE) recently issued a National Exam Program Risk Alert that discusses the eight most frequent best execution-related compliance issues identified in deficiency letters from more than 1,500 adviser examinations. In addition to summarizing OCIE’s findings, this article provides guidance on how advisers can avoid similar errors from an industry practitioner with expertise in this area. For more on other recent OCIE Risk Alerts, see “Six Most Frequent Fee and Expense Compliance Issues” (May 3, 2018); and “Six Most Frequent Advertising Rule Compliance Issues” (Oct. 19, 2017).