This study examined the hypoglycemic effect of Moringa olieifera leaves in the subjects with impaired fasting glucose or mild type 2 diabetes using an oral glucose tolerance test (OGTT). Seventeen participants (six males and eleven females) participated in the study. The mean age of participants was 54.12 ± 5.85 years. The mean levels of fasting plasma glucose (FPG) and glycosylated hemoglobin (HbA1c) of the participants were 118.18 ± 12.97 mg/dL nd 6.10 ± 0.53% respectively. The participants twice took an OGTT, at baseline (1st visit) and after taking four capsules of M. oleifera leaves 450 mg (2nd visit). Blood samples were drawn to measure plasma glucose levels at 0, 30, 60, 90, 120, 150, and 180 minutes after taking 75 g of glucose. The results showed that plasma glucose levels at 90, 120, and 180 minutes after the oral administration of M. olieifera were significantly lower than those at baseline (p = 0.026, p = 0.047, and p = 0.028 respectively). However, M. oleifera also decreased peak plasma glucose levels at 60 minutes but not significantly (p = 0.142). In conclusion, the results indicated that M. oleifera influences levels of blood sugar; consequently it may be beneficial for diabetic patients as an alternative in the control of blood glucose levels.