Fitness clubs have emerged and become popular in response to Taiwanese health needs. Improving service quality and increasing customer loyalty to enhance competitive advantage in the market is a major topic for fitness industry owners. The purpose of this research is to verify the relationship between service quality and customer loyalty in the Taichung fitness club. This study adopted a questionnaire survey method. The questionnaire was developed based on previous studies. Respondents were selected by convenient sampling within large-scale chain fitness clubs, small gyms, and national sports centres. This study used online questionnaires and hard-copy questionnaires to collect data, and a total of ninety-four valid questionnaires were obtained. The collected data is analyzed by descriptive statistics, correlation analysis, and partial least square structural equation modelling. This study found that the service quality of tangibility, reliability, responsiveness, certainty, empathy are all significantly positively correlated with customer loyalty; responsiveness and empathy service significantly influence customer loyalty. The conclusions of this study indicate that although service quality has a positive correlation with customer loyalty, responsiveness and empathy are important factors to improve customer loyalty in fitness clubs.