FOR SOME TIME NOW, THE AUDIT SERVICES MARKET HAS AROUSED GREAT INTEREST AT THE INTERNATIONAL LEVEL, AND AN IMPORTANT ISSUE IN THIS MATTER HAS BEEN THE ROTATION OF THE BIG FOUR (B4 FIRMS: PWC, EY, DELOITTE AND KPMG). THE OBJECTIVE OF THIS RESEARCH IS TO PROVIDE EMPIRICAL EVIDENCE ABOUT THE TURNOVER OF B4 FIRMS IN COMPANIES AUDITED BY THE FINANCIAL MARKET COMMISSION (CMF) IN CHILE. THE IMPORTANCE OF THIS WORK IS THAT IT IS FRAMED IN A LINE OF RESEARCH WITH AN ABSENCE OF WORKS IN CHILE, IN ADDITION, IT INSTALLS A DEBATE AT NATIONAL LEVEL. THE APPROACH IS QUALITATIVE; A COLLECTION AND ANALYSIS OF DATA ON 381 COMPANIES OF THE CMF IS CARRIED OUT AND THE PERMANENCE OF THE AUDIT FIRMS IN EACH ONE IS QUANTIFIED WITH A LONGITUDINAL SCOPE FROM 2010 TO 2019. THE TYPE OF THIS RESEARCH IS EXPLORATORY IN NATURE. THE FINDINGS REVEAL THAT B4S REMAIN FOR LONG PERIODS OF TIME IN CMF COMPANIES AND, IN ADDITION, THERE IS NO AUDITOR ROTATION REGULATION, WHICH MAY LEAD TO THE FACT THAT, IN CHILE, AS IN OTHER COUNTRIES, IT IS GENERATING ENTRY BARRIERS TO OTHER SMALLER FIRMS, BECOMING AN OLIGOPOLISTIC MARKET AS IN THE INTERNATIONAL AUDIT MARKET.