ISH is the most common type of hypertension in people over 60 years of age and increase in SBP being the principal characteristic in this population. Interestingly, data from a number of studies suggest that ISH is also prevalent in adolescents and young adults but findings from previous studies examining this question are inconclusive, so the aim of our study is to know prevalence and determinants of ISH in young healthy individuals. Method: We performed a cross section study on 400 young individuals between 18 to 30 years in western Rajasthan. The participants were then subjected to a set of questionnaire which included socio-demography determinants (age, sex, occupation and annual household income), personal habits (dietary habits, smoking, alcohol consumption), past history and family history of hypertension. They were then subjected to the measurement of height, weight, pulse rate, blood pressure, fasting blood sugar and serum cholesterol level. Result: In our study 9.25% were hypertensive (systolic, diastolic or both systolic and diastolic) and from this ISH were 4.25%, IDH were 1.5%, SDH were 3.5%, systolic hypertension in 7.75% and diastolic hypertension in 5%. Conclusion: ISH have quite high prevalence in young adults and is more common than SDH. Female gender, rural in-habitants, non-vegetarian diet, low socio-economic status, family history of hypertension, smoking, alcoholism, BMI and Serum Cholesterol level are important determinants of ISH in young adults.