Using the criteria of weight(g)/height(cm)2 greater than or equal to 2.26 as cut off point, 292 (7.56%) of the 3,861 school children in the age group 5-15 years were identified as obese. The mean blood pressure levels, both systolic and diastolic, were found to be significantly higher in the obese subjects compared to the controls (p less than 0.001). Further, 10 (3.4%) of the 292 obese subjects were detected to have sustained elevations in BP levels (BP greater than mean + 2 SD for age-sex) on monthly follow-up for 6 months. On the contrary, persistent hypertension was detected in only six (0.16%) of the 3,569 controls. None of these hypertensive children had any symptoms attributable to raised blood pressures and all had only mild elevations in BP levels. Baseline investigations, carried out in 9/16 subjects, failed to document any underlying cause for hypertension. Serum cholesterol levels, however, were elevated in six subjects. This suggests a close association between childhood obesity and essential hypertension.