Background: Most children who have congenital heart disease in low-and middle-income countries (LMICs), including Uzbekistan, do not receive adequate and timely pediatric cardiac surgical care. To strengthen the surgical capacity of a local pediatric cardiac surgery team in Tashkent, Uzbekistan, the JW LEE Center for Global Medicine at Seoul National University College of Medicine has developed a team-based training program and has been collaboratively conducting surgeries and care in order to transfer on-site knowledge and skills from 2009 to 2019. Objectives: To evaluate the long-term effects of the collaborative program on the cardiac surgical capacity of medical staff (teamwork, surgical complexity, and patients' pre-surgical weights) as well as changes in the lives of the patients and their families. To derive lessons and challenges for other pediatric cardiac surgical programs in LMICs. Methods: To assess the effects of this ten-year long program, a mixed-methods design was developed to examine the trend of surgical complexity measured by Risk Adjustment for Congenital Heart Surgery 1 score (RACHS-1) and patients' pre-surgical weights via medical record review (surgical cases: n = 107) during the decade. Qualitative data was analyzed from in-depth interviews (n = 31) with Uzbek and Korean medical staff (n = 10; n = 4) and caregivers (n = 17). Findings: During the decade, the average RACHS-1 of the cases increased from 1.9 in 2010 to 2.78 in 2019. The average weight of patients decreased by 2.8 kg from 13 kg to 10.2 kg during the decade. Qualitative findings show that the surgical capacity, as well as attitudes toward patients and colleagues of the Uzbek medical staff, improved through the effective collaboration between the Uzbek and Korean teams. Changes in the lives of patients and their families were also found following successful surgery. Conclusions: Team-based training of the workforce in Uzbekistan was effective in improving the surgical skills, teamwork, and attitudes of medical staff, in addition, a positive impact on the life of patients and their families was demonstrated. It can be an effective solution to facilitate improvements in pediatric cardiovascular disease in LMICs if training is sustained over a long period.