ABSTRACT This study aims at showing the effect of merger and acquisition operations on Jordanian public shareholding companies by analyzing this effect on audit fees and on the company’s auditor's opinion before and after mergers. The society and sample of the study consists of all public shareholding companies listed in the Amman Stock Exchange, which underwent the process of integration during the period from 2009 to 2016. To achieve the objectives of the study, the researchers conduct a descriptive statistics, correlation analysis, multiple regression analysis and non- parametric tests to test the hypothesis in relation to the auditor's opinion. Parametric tests are used to test the hypothesis in relation to the auditor's fee, the McNamar test, and the Pearson correlation matrix. The results of the study show a positive effect of the merger process and the acquisition of audit fees, a positive effect of the ratio of receivables to total assets, size of the company and size of the audit office on audit fees, absence of impact on return on assets, and the number of subsidiaries on audit fees. Based on the results of the study, several recommendations are proposed of which the most significant is the encouragement of audit offices in Jordan in connection to international and specialized auditing offices which have expertise in mergers and acquisitions. Keywords: Audit fees; audit opinion; mergers and acquisitions; public shareholding companies; Jordan