Quality improvement (QI) is a systematic, data-driven approach to improve the delivery of healthcare services. QI interventions are now being implemented more frequently in lower-income countries. Although research has demonstrated the effectiveness of QI strategies in improving care quality and patient safety, studies also reveal variation in the success of QI interventions. The goal of this dissertation was to add to our understanding of factors related to the effectiveness of QI teams in lower-income countries and to support efforts to spread the use of QI methods to these settings. The sample consisted of 559 individuals from 127 teams established as part of Project Fives Alive!, a nationwide program in Ghana to reduce mortality in children under 5 years of age by promoting low-cost, high-impact, evidence-based practices. This dissertation used structural equation modeling to accomplish three aims regarding the evaluation of hospital-based QI teams in Ghana. The results from the first analysis demonstrated that survey tools developed in high-income countries can be adapted to evaluate QI teams from lower-income countries. The results from the second analysis showed that slack resources are positively associated with perceived support for teamwork and with coaching-oriented team leadership. The results from the second analysis also motivated two additional multidimensional characteristics of the slack resources construct. Finally, the third analysis provided additional evidence in support of the model of work-team learning, demonstrating that 1) team psychological safety mediates a positive relationship between coaching-oriented team leadership and team learning behavior and that 2) team learning behavior mediates a positive relationship between team psychological safety and the implementation of QI methods. The results of this dissertation have theoretical and practical implications. This dissertation addresses the call to use theory to explore team-level determinants of QI implementation and extends the model of work-team learning to lower-income countries. The findings address real-world problems and identify potential leverage points that could be targeted to support efforts to implement similar QI interventions in other countries.