India is a developing nation and a young nation. It is important to have a healthy young population to prevent development of various lifestyle diseases in future. The present study aimed to see the correlation of BMI with obesity and physical activity patterns in 200 university male students (18-27 years) in Hisar city. The results showed that of the total population 16% and 9.5% of the students were overweight and obese. There was strong positive correlation between BMI and Waist circumference (p<0.01) and BMI and hip circumference (p<0.01). While, there was a negative correlation between BMI and physical activity, though non-significant. Hence, young boys should be advised to be more physically active to prevent rise in BMI and hence associated obesity in the long run.