Introduction:-TMD is the main cause of pain of non-dental origin in the oro-facial region and is multifactorial in nature. Orthodontic treatment has been linked to TMD since 1980s, which started a series of studies to find out any co-relation between orthodontic treatment and TMD. Objective:-To determine the prevalence of TMJD in patients during or after fixed orthodontic treatment in Qassim Area. Materials and Methods:-It was a cross sectional study done on 232 orthodontic patients. Data collection was done by self-administrated questionnaire. Result:-Data analysis was done by SPSS version 22.Results showed there was no significant co-relation between TMD and orthodontic treatment. Conclusion:-Orthodontic treatment is not a cause of TMD.