<p> After decades of global intervention to conquer diseases, healthcare in many countries is still lacking. Assessments of medical laboratories in developing countries today find poor infrastructure conditions with no standardized processes or quality assurance to guarantee accurate results and enable quality healthcare. Bringing healthcare programs in developing countries up to international standards remains a challenge. </p><p> Currently, there is a scarcity of scientific research related to the determinants of success in implementing quality management systems (QMS). There has been little research dedicated to identifying the critical success factors for medical laboratories striving to improve the accuracy and reliability of their testing services in developing countries. </p><p> In over nine years of research, the author realized there was a need for incorporating Critical Success Factor (CFS) methodology into laboratory modernization efforts. This time frame included CDC sponsored trips to several African countries and collaborating with the Vietnam Administration for Medical Services/Ministry of Health (VAMS), Centers for Disease Control-Vietnam (CDC-vn) and seven universities to build laboratory capacity and initiate laboratory improvements to meet national and international laboratory standards. In 2017, VAMS approved a proposed study to identify CSFs in four laboratories in Vietnam. </p><p> The research question this study sought to answer was "What are the top five critical success factors for successful implementation of QMS into laboratories in Vietnam?" with an outcome of improved accuracy and reliability of testing results. This study utilized both qualitative and quantitative research methods employing principles of descriptive research. A demographic survey, semi-structured interview, content analysis, and benchmarking were utilized to identify the top five CSFs and barriers. Content analysis was employed to review CSF definitions and categorize all 220 listed CSFs into ten comprehensive and mutually exhaustive categories. Two research assistants assisted the researcher place each CSF into one of the ten categories. Rigorous and non-rigorous methods measured interrater reliability with the categorization of CSFs. Cohen Kappa values were > 0.85 indicating excellent reliability and accuracy between the assistants and the researcher. Chi-square values were all > 0.05 (p &lt; 0.05) indicating demographic variables did not statistically impact findings. </p><p> Qualitative responses were gathered through personal interviews, a demographic survey, and benchmarking. Using a stratified convenience sampling, participants represented four levels of stakeholders: laboratory staff, laboratory managers, hospital administrators, and clinicians utilizing laboratory services. </p><p> Data from this study found the top five CSFs were: staff knowledge of QMS, laboratory management leadership knowledge and skills, staff commitment to the QMS change process, mentorship, and hospital administration support. In addition to determining the top five CSFs, the study revealed information about encountered or perceived barriers to successful QMS implementation. The participants in this study identified lack of staff knowledge on QMS, lack of financial support from the hospital administration, ineffective laboratory manager leadership knowledge and skills, lack of laboratory infrastructure, and lack of sufficient resources. </p><p> The study&rsquo;s findings add to the body of knowledge in strengthening medical laboratory services and may serve as a basis for continued research in this area of health care. Local, national, and international partners may use this information to tailor training materials and activities to better meet the needs of participating laboratories across Vietnam.</p><p>