Abstract:This study attempted to evaluate the mediating role of CRM (Customer Relationship Management) quality in discovering the effects of the variables in service quality for internet service providers on customer loyalty. The service quality on internet serviceproviders are network quality, customer service & technical support, information & website support and privacy & security. Data was obtained from 476 respondents of fixedbroadband ISP (Internet Service Provider) users atIndonesiaon April 2020. The SmartPLS 3.0 Software was carried out to exam the hypotheses using bootstrapping method of 5000 random samples. The results of the analysis indicated that the mediating role of customer relationship management quality has strong impactonservice quality to customer loyalty. Moreover, the contribution of thisresearch from the modelling of the mediation will be usefull for any internet providers who wants to deploy their strategy to increase theircustomer loyalty.