ObjectivesThis study examined the predictors, the barriers, and the motivating factors of adherence to the gestational diabetes mellitus (GDM) management plan among Arab pregnant women with GDM. MethodsThis cross-sectional study was conducted in the Antenatal Clinics of three major tertiary hospitals in Oman. Total of 164 Arab pregnant women with GDM were recruited using a convenience sampling technique. The measurement scales included Diabetes Self-Management Questionnaire- Revised, Diabetes Management Self-Efficacy Scales, and Social Support Survey. Multiple-choice questions were used to assess barriers to and motivators of adherence. The analytical tools included multiple linear regression and descriptive statistics. ResultsFindings from stepwise regression analysis revealed three models with three significant predictors, including self-efficacy, previous history of GDM, and the type of GDM management. The major barriers to adherence were family, especially kids' responsibilities, time constraints, home responsibilities, and working status. Moreover, participants indicated their concern about maternal and neonatal GDM-related complications and husband encouragement as the main motivating factors for adherence. Conclusionsand Clinical Relevance: Our findings suggest that antenatal healthcare providers should implement strategies that enhance self-efficacy and engage families in health education programs. The study also recommends collaboration between health policy makers in the Ministries of Health, Consumer Protection Agency, and the Ministries of Municipality to ensure the availability of healthy food choices in the public areas. Additionally, flexible working conditions and an environment conducive to a healthy and active lifestyle should be made available to pregnant women with GDM.