Goal: To determine the prevalence of underweight and short stature in school, as well as lifestyle and socioeconomic factors that influence them. Methods: We conducted a survey on a sample of 1237 students aged 12 to 19 years of public and private colleges in the city of Settat. The underweight and short stature were respectively defined by the threshold index lower BMI body mass on the 3rd percentile for age and gender of the French reference corpulence curves, and the size threshold is lower 3rd percentile for age and sex of L WHO waist curves Results: The total enrollment of students is 1237, 644 girls and 593 boys, with 364 private and 873 public. The mean age was 14.7 years in public (14, 5 years old girls and 14.9 years old boy) and 13.6 years in private .The prevalence of underweight and short stature are more common in students in public schools; 2.62% underweight and 8.57% of stature against 1.65% underweight and 4.69% of stature among students in private colleges. Male dominance is statistically significant for short stature; 13.58% for boys against 3.79% in girls. Conclusion: Although the prevalence of underweight and short stature in Morocco is regarded as low, it exists.; thus, prevention and the deployment of the control measures are necessary so as avoid health problems as the case in the underdeveloped countries.