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Objective: Malocclusion is a common oral disorder, can cause negative impacts on oral conditions, social life and patients ` self confidence. The objective of this study was to determine whether orthodontic treatment influence oral health re-lated quality of life (OHQoL). Materials and Methods: Cross-sectional design with self-reported data were col-lected from 302 participants attended at professional orthodontic office (62 % fe-male; mean age, 21.71 years) in two “treatment ” and “no treatment ” groups. The measure namely (oral health impact profile) OHIP-14 was used to assess the pa-tient`s OHQol. Linear regression model was used in the data analysis. Results: A significant relationship was found in one question and one domain of OHIP-14 between the two groups (P<0.05) which showed difference in physical limitation. Linear regression model showed that in the treatment group, this do-main of OHQoL was 1.86 times less likely complicated than in the “no treatment” group. Conclusion: Patients who had completed orthodontic treatment had a better OH-QoL in physical aspects than those who never had treatment