Objectives: To determine the effect of junk food on the nutritional status of 12 years old girls. Background: Junk food has become a prominent feature of the diet of children worldwide. The ready availability, taste, low cost, media, and peer pressure make them popular among children. Junk food is widely available everywhere making it first choice for not only children but also adults. The fats, sugar, and salt in junk food draw kids like a magnet. Obesity in children has increased threefold or more during the last three decade raising serious public health concerns. Junk food consumption may be one of the contributing factors to this problem. Materials and Methods: A cross-sectional study was conducted in a government school in Quetta. Total fifty girls of the same age (12 years) were selected for the study. Their age was taken from the school record. Standardized Questionnaire was used which included 10 questions and 24-hour dietary recall form was filled. Height and weight of students were recorded according to standard methods. BMI was recorded using standard height and weight formula. Results: The results of weight according to age in percentile was as 28% (14) girls were at the 5th percentile. 34% (17) were below the 5th percentile for age. 28% were between 5th and 50th percentile for age, 10% (5) were between 60 and 70th percentile. The results of height in percentile was like 40% (20) girls were at the 5th percentile of height for age,20%(10) were between 5th and 50th percentile,10%(5) were between 60th and 75th percentile. 10%(5) were at 75th percentile. Conclusion: From this study, it is evident that problems in this area are somewhat different. Although snacking with junk food, use of unhygienic food, intake of empty calories are the same issues but obesity is not our problem rather our kids are underweight and stunted due to inadequate caloric intake, and poor quality food. Unemployment, lack of education and big families all are contributing factors to poor quality diet.