Objectives: To examine patients’ and parents’ perceptions and expectations from orthodontic treatment. Study Design: 491 patients (274 female, 217 male) aged 14–22 years, and 399 parents (245 female, 154 male) completed a questionnaire about preferences, needs and expectations about orthodontic treatment, and scored the present problem. Continuous variables were compared by Mann-Whitney U and Kruskal-Wallis tests, whereas Chi-square test was used for categorical variables. Results: Patients’(77.1%) and parents’(84.6%), decision about orthodontic treatments were influenced by suggestion of dentists. Patients who decided to attend to clinic by themselves were higher than parents (p=0.006). Dental aesthetics was the determinant factor for treatment demand for patients(61.0%) and parents(57.3%). Improvement in oral functions was more important for Class III patients than Class I patients (p=0.040). Adult patients/parents with higher education gave more importance to oral functions as well as dental aesthetics (p=0.031). There was no difference among Angle classifications regarding orthodontic problem scores. Parents found media sources valuable (p=0.018) but majority expected dentists for information about orthodontic treatments. Education degree of adult patients/parents effected this decision(p=0.002). Conclusions: Desire to have better dental aesthetics was the primary motivating factor for all participants. Clinicians should consider concerns of Class III patients about oral functions during treatment planning.