Background: Gestational diabetes mellitus (GDM) is defined as glucose intolerance of variable degree with onset or first recognition during pregnancy. The precise mechanisms underlying gestational diabetes remain unknown. The hallmark of GDM is increased insulin resistance. Pregnancy hormones and other factors are thought to interfere with the action of insulin as they bind to the insulin receptors. Uric acid is the end product of purine catabolism catalyzed by the enzyme xanthine oxidase/dehydrogenase. Objective: The aim of the study was to determine whether uric acid level in the first trimester of pregnancy can be used as a predictor of subsequent development of GDM or not. Patients and methods: This was a prospective observational cohort study which included 520 pregnant women in their first trimester who regularly attended the outpatient clinic for routine antenatal care. This study was conducted at Alexandria Police Authority Hospital from November 2018 to May 2020. Results: Elevated first-trimester uric acid concentration was correlated with an increased risk of developing GDM. The risk of developing GDM was 4-fold higher if first-trimester uric acid was ≥ 3.05 mg/dl [OR 3.8, 95% CI (1.99 to 9.15)]. There was a significant positive correlation between serum uric acid and BMI (r = 0.378). The mean BMI was significantly higher in women who developed GDM when compared to women who did not develop GDM [29.02 ± 4.39 Kg/m2 vs. 26.04 ± 4.16 Kg/m2, respectively]. There was no statistically significant relationship between age and development of GDM. Serum uric acid at recruitment was insignificantly associated with a fasting blood glucose ≥ 105 mg/dl among women who developed GDM [OR 0.833, 95% CI (0.493 to 1.47)]. Conclusion: In pregnancy, uric acid is correlated with insulin resistance in women with gestational hypertension and is higher at 24-28 weeks gestation in women diagnosed with GDM compared to women without diabetes.