This paper empirically evaluates the effects of various merger and acquisition (M&A) advisors on perceived M&A success by using survey data from M&A experts around the globe. The dataset includes three different M&A advisor types including legal/tax/audit advisors, financial advisors, and, most importantly, strategy consultants. In addition, we are able to employ a comprehensive control framework that considers the functional setup of the M&A organization of firms, e.g., whether M&A activities are organized at the headquarters or at the business unit level. Our main results show that, ceteris paribus, strategy consultants increase M&A success by up to 3.7%, thereby exceeding benefits from other M&A advisors, such as financial advisors by more than one percentage point. Finally, M&A success is improved the most if M&A advisors are hired regularly. The effects from the M&A advisors are partially mediated by the M&A process standardization channel.