Thailand is one of the Southeast Asia countries that has been significantly impacted by Registered Nurse (RN) workforce shortages. This integrative review aims to critically analyze factors influencing the attrition and retention of RNs practicing in Thailand's hospital sector. The databases searched included CINAHL (via EBSCOhost), EMBASE, Nursing Allied (via ProQuest), Ovid, Scopus, Web of Science, and Medline. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) were utilized to record the search strategy findings in compliance with the review standards, while the Mixed-Methods Appraisal Tool (MMAT) was used to appraise quality. Sources for review totaled 35, using quantitative methods (n = 30), qualitative methods (n = 3), and mixed methods (n = 2). Thematic analysis revealed factors that challenge RNs' job motivation fueled by a lack of autonomy, a loss of confidence and sense of competence, and negative workplace relations with co-workers, resulting in poor job satisfaction. Future research is needed to elicit an understanding of "how" Thai RNs sense of autonomy, competence, and relatedness in their workplace practice provides insight into "why" they choose to remain employed or leave the nursing workforce.