The study was undertaken to see the prevalence of impaired glucose tolerance among children and adolescents with obesity, attending the Paediatric Endocrine OPD, Bangladesh Institute of Research and Rehabilitation in Diabetes, Endocrine and Metabolic disorders (BIRDEM), Dhaka, Bangladesh. A cross sectional study from January 2006 to December 2008 was conducted among obese children and adolescents (6-18 years). Children with any other endocrine disorder, dysmorphism/syndrome were excluded. Obesity was defined as BMI ≥ 95th percentile for age and sex using CDC growth chart. Children underwent two hours oral glucose tolerance test with 1.75 gm/kg or 75 gm of glucose, anthropometric and blood pressure measurement. Fasting serum insulin and lipid profile were measured. Impaired glucose tolerance (IGT) was defined as fasting plasma glucose (FPG) <7 mmol/L and 2 hours post glucose load ≥ 7.8 mmol/L to <11.1 mmol/L. Diabetes mellitus (DM) was defined as FPG ≥ 7 mmol/L or 2 hours post glucose load ≥ 11.1 mmol/L. Homeostasis model assessment was used to estimate insulin resistance. A total of 161 children presented with obesity. Male to female ratio was 1.3:1. Mean age was 10.3 ± 2 .5 years. Mean BMI was 27.86 ± 4.1 kg/m². IGT was found in 16.9% of children and adolescents. In children aged 6-10 years IGT was detected in 16.1% and in adolescents aged 11-18 years IGT was detected in 20%. Diabetes mellitus was detected in 2.1% of subjects, all were adolescents. Serum fasting insulin and hip circumference were significantly higher among children and adolescents with IGT compared to that of normal glucose tolerance. The high rate of IGT among obese children and adolescents is of concern. Factors contributing towards obesity needs to be identified and strategies should be planned for prevention and management of this health problem.