: The objective of this survey was to assess the orthodontic treatment need in school children of Shimla aged 12-16 years using Index of orthodontic treatment need.The study included 576 children studying in Shimla, Himachal Pradesh, India who were assessed for orthodontic treatment need using IOTN and results were expressed in percentages. The difference in orthodontic treatment need for males and female and the orthodontist and subjects perception of orthodontic treatment need was calculated by χ² test. Pearson’s correlation assessed the correlation between the Dental Health Component and Aesthetic Component of IOTN. 10.7% (62) of the children had definite need for orthodontic treatment (AC) while 31.9% (184) had definite need for orthodontic treatment (DHC) with statistically insignificant difference between male and female. The difference between orthodontist perception of treatment need and that of subject was statistically significant. A strong and positive correlation between DHC and AC of IOTN was found which was statistically significant.31.9% (184) and 10.8% (62) of the schoolchildren had definite need for orthodontic treatment according to the dental health component and aesthetic component of index of orthodontic treatment need respectively. 49.7% (286) of the subjects had knowledge about orthodontic treatment. 45.8% (264) of the subjects expressed desire to undergo orthodontic treatment. Orthodontist was more critical in aesthetic evaluation as compared to the schoolchildren.