The rate at which private hospitals are failing to satisfy and retain their customers is becoming a concern for hospital managers. Customer satisfaction and retention issues have affected most private hospitals leading to customer defection. For organizations to have a competitive edge over their competitors, they need to focus on customer satisfaction and retention to reduce customer defections. The general objective of the study was to evaluate the antecedents of satisfaction and retention of customers in Outspan Hospital in Nyeri County, Kenya. The study was guided by the Service Quality Gap Model. The study used a descriptive research design. 70 respondents acting as heads and deputies of the various departments of Outspan Hospital consisted of the target population. A census method was used hence the assumption of 70 respondents as the sample size. Structured questionnaires were used to collect data. Inferential statistics which included variance, and regression analysis were used to measure the existence of a relationship between the independent variables, and the dependent variables. The study findings established that three independent variables namely; service design, system usage, and customer switching cost were significantly associated with customer satisfaction and retention in Outspan hospital. Therefore, the management of Outspan Hospital should enhance customer satisfaction and retention based on key study recommendations. These recommendations include; improving the external appearance of the institution, focusing on improving complaints handling programs, improving utilization of self-service technology (SST), and retaining customers through switching barriers that provide customers with superior customer value.