Background: During the last 2 decades overweight and obesity have increased globally among children and adolescents. Methods: This was a descriptive, cross sectional study conducted during the period October 2012 to January 2013 among two high schools in Khartoum state. A total of 425 students from both schools were included in the study. Data was collected using a questionnaire, stadiometer and a measuring scale and body mass index was calculated. Data analysis was performed using SPSS program. P value was set on at 0.05 level of significance. Results: The results revealed that nearly one fourth of high school girls were overweight/obese, with the proportion slightly higher in the private school, also most of the students consider obesity a risk factor for hypertension, heart disease and breathing problems. Most of the girls in our study indicated a clear desire to lose weight. Conclusion: Public health programs are needed to increase awareness on risk factors for overweight and obesity among children and adolescents in order to reduce the future burden of obesity-associated chronic diseases.