Recent studies in the Sub-Saharan countries in Africa have indicated gaps and challenges for voluntary medical male circumcision (VMMC) quality of service. Less has focused on the changes in quality of service after implementation of continuous quality improvement (CQI) action plans. This study aimed to evaluate the impact of coaching, provision of standard operating procedures (SOPS) and guidelines, mentoring and on-site in-service training in improving quality of VMMC services across four Right to Care (RTC) supported provinces in South Africa. This was a pre- and post-interventional study on RTC supported VMMC sites from July 2018 to October 2019. All RTC-supported sites that were assessed at baseline and post-intervention were included in the study. Data for baseline CQI assessment and re-assessments was collected using a standardized National Department of Health (NDoH) CQI assessment tool for VMMC services from routine RTC facility level VMMC programme data. Quality improvement support was provided through a combination of coaching, provision of standard operating procedures and guidelines, mentoring and on-site in-service training on quality improvement planning and implementation. The main outcome measure was quality of service. A paired sample t-test was used to compare the difference in mean quality of service scores before and after CQI implementation by quality standard. A total of 40 health facilities were assessed at both baseline and after CQI support visits. Results showed significant increases for the overall changes in quality of service after CQI support intervention of 12% for infection prevention (95%CI: 7-17; p<0.001) and 8% for male circumcision surgical procedure, (95%CI: 3-13; p<0.01). Similarly, individual counselling, and HIV testing increased by 14%, (95%CI: 7-20; p<0.001), group counselling, registration and communication by 8%, (95%CI: 3-14; p<0.001), and 35% for monitoring and evaluation, (95%CI: 28-42; p<0.001). In addition, there were significant increases for management systems of 29%, (95%CI: 22-35; p<0.001), leadership and planning 23%, (95%CI: 13-34; p<0.001%) and supplies, equipment, environment and emergency 5%, (95%CI: 1-9; p<0.01). The overall quality of service performance across provinces increased by 18% (95%CI: 14-21; p<0.001). The overall quality of service performance across provinces was significantly improved after implementation of CQI support intervention program. Regular visits and intensive CQI support are required for sites that will be performing below quality standards.