SUMMARY Glucose intolerance in pregnancy is a high risk condition with increase maternal and perinatal morbidity and mortality. This condition is affected by obesity amongst other risk factors. This cross sectional analytical study was undertaken to determine the influence of obesity using the body mass index (BMI) on glucose intolerance among women attending the antenatal clinic of the University of Benin Teaching Hospital, Benin City. The subjects or cases were 50 women with BMI >27kg/m2 considered as high while the controls were also 50 women with BMI <27kg/m2 . Both the cases and controls then underwent the 75g Oral Glucose Tolerance Test at between 24-28 weeks gestation. Findings from the study showed association between obesity, age, parity and social class with the obese subject being older, of higher parity and in higher social class than the controls though the sample size was not large enough to make conclusions. The blood glucose levels were essentially normal in all five point of the oral glucose tolerance test with good glucose disposal both in the obese and controls though the values were generally higher in the obese. There were however no cases of either impaired glucose tolerance or gestational diabetes mellitus detected. This poor association between BMI and glucose intolerance as shown in this study brings to question the benefit of routine screening of glucose intolerance in pregnancy based on maternal weight or BMI alone in our environment considering the cost and the poor yield