The data on these risk factors in school age population is deficient in India. The present study was conducted to evaluate the prevalence of lifestyle associated risk factors for non-communicable diseases in apparently healthy school children in an urban school in Delhi using standard criteria.The study was carried out among 510 students of classes 9th-12th of a school in New Delhi and in the age group of 12 to 18 years. The students were surveyed through an age appropriate modified GSHS (Global School Based Student Health Survey) self administered questionnaire. Height and Weight were measured using standardized equipment and procedure. The blood pressure was measured using OMRON electronic B.P apparatus which were standardized daily against a mercury sphygmomanometer. The statistical analysis was done using Epinfo ver.3.3 and SPSS ver11.5.The study documents the inappropriate dietary practices (fast food consumption, low fruit consumption), low physical activity, higher level of experimentation with alcohol and to a lesser extent smoking, high prevalence of obesity and hypertension in the school children. The study also showed an association between BMI, systolic and diastolic blood pressures amongst children and other lifestyle factors.School based interventions are required to reduce the morbidity associated with non-communicable diseases.