Objectives: We sought to conduct a detailed study on the risk factors of gestational diabetes mellitus (GDM) in Omani women to determine the actual and applicable risk factors and glucose profile in this population.  Methods: We conducted a cross-sectional case-control study using pregnant women diagnosed with GDM. Pregnant women without GDM were used as a control group. We collected information related to age, family history, prior history of pregnancy complications, age of marriage, age of first pregnancy, fasting glucose level, and oral glucose tolerance test (OGTT) results from three hospitals in Oman through face-to-face interviews and hospital records. Results: The median age of women with GDM was 33 years old (p < 0.050). A significant risk was noted in women with a history of diabetes (p < 0.001), and those with mothers' with a history of GDM. A significant (p < 0.010) relationship with a likelihood ratio of 43.9 was observed between the incidence of GDM in women with five or six pregnancies, a history of > 3 deliveries, height < 155 cm, and pregnancy or marriage at age < 18 years (p < 0.010). The mean difference in random plasma glucose, one-hour OGTT, and two- hour OGTT was significantly higher in GDM cases compared to control. Conclusions: Glucose profile, family history, anthropometric profile, and age of first pregnancy and marriage should be considered while screening for GDM and determining the care needs of Omani women with GDM.