Background: Acne  vulgaris  is the  most  common  dermatological   condition  encoun- tered  in adolescents.

Aim: It was to determine the prevalence of acne vulgaris and its impact of the quality of life among adolescents attending secondary schools in Sohag Province, Upper Egypt. Patients  and  methods: This  was  a  cross-sectional  study   conducted  in  randomly selected  governmental and  technical  secondary schools  in Sohag  Province,  Upper Egypt. Approval was  taken  from the  scientific  research committee of Sohag  Faculty of Medicine  and also from Ministry of Education.  Every student with acne  was sub- jected  to  full medical  history  and  local examination  of head  and  neck  to  assess  the severity  of acne  vulgaris. Assessment of the  impact  of acne  vulgaris on their  quality of  life  was   carried   out   using  self-reported  validated   specific   questionnaire, the Cardiff Acne Disability Index (CADI).

Results:  This  study  included  994  teenage  secondary school  students. The  overall prevalence of  acne  vulgaris  was  333  (33.5%). The  mean  age  of  the  students with acne  was 16.84   0.87. Acne vulgaris was more  common  among  females  than  among males  (200,  60%  vs 133,  40%). The  most  common  form  of acne  vulgaris was  mild178,  53%,  followed  by  moderate form  135,  41%,  and  severe   form  20,  6%. CADI score  was  significantly  related   to  the  disease   grade  and  it  was  maximum  among those  with severe  grade, followed  by moderate and lastly mild disease  grade. Conclusion:   Acne  vulgaris is a common  skin disease  and  has  a valuable  impact  on quality  of  life among  adolescents attending secondary schools  in Sohag  Province, Upper  Egypt.