Objective: To investigate the prevalence of acne, related factors and psychological impact on the pupils at Chau Van Liem Senior High School. Method: A cross sectional study on 405 pupils in 10th, 11th, 12th, class was carried out by means ofmedical examination, and interviews based on questionnaires. Results: The prevalence of acne in Chau Van Liem Senior High School students was 82.5 percent overall. Separately, the incidence was slightly higher for boys (83.9 percent) than girls (87.7 percent). Most of these pupils had moderate acne (57.5 percent) and 46.7 percent having mild acne. Only 7.8 percent of them had the disease at severe. Moderate acne was 7.72 times more common in males than females. The essential lesions included oily skin, comedone, papules, hypepigmentation and/or scar. One risk factor associated with acne was identified as the habit of using cosmetics. The research also identified the differences between boys and girls in their habits con cering: facial massage, using facial milk and cosmetics. Acne could be the cause of depression and ashamed. Boys with acne were less communicative than girls. Conclusion: The prevalence of acne in Chau Van Liem Senior High School pupils is 82.5 percent. Pupils still display bad habits such as squeezing, applying cosmetics, using mixed - cream bought fram the store or self concocted mixtures of locally obtainable creams including steroids, aspirin, antibiotics, vitamins which lead to harm for the skin. Acne also affects their psychological health, emotion performance in school, family relationships as well as friendships.