AIMS: To determine the association and level of agreement between young adults' perception of orthodontic treatment need (subjective need) and the orthodontists' assessment of treatment need (normative objective need). METHODOLOGY: For this study, 670 students [280 males and 390 females; mean age (standard deviation) of 15.32 (1.81) years] were selected from public and private schools from different demographic areas of Jeddah city, Saudi Arabia, and divided into two age groups (12–15 years) and (16–19 years). All the participants were examined, and the Index of Orthodontic Treatment Need (IOTN) components [dental health component (DHC) and aesthetic component (AC)] were recorded. RESULTS: Kappa statistics showed a statistically significant but fair agreement between clinician AC (CAC) and student AC (SAC) assessments in both age groups (k = 0.343 and 0.334, respectively; P < 0.001), whereas Spearman's correlation coefficient showed a statistically significant but moderate association (r = 0.487 and 0.517, respectively; P < 0.001). The degrees of agreement were 76.4% and 76.7% at the no-need and mild-need levels of treatment, respectively. There was a statistically significant but weak association between the subjective and normative needs (SAC and IOTN-DHC) in both age groups (r = 0.336 and 0.360, respectively; P < 0.001). However, the degrees of agreement were 58.9% and 61.5% at the no-need and mild-need levels of treatment, respectively. CONCLUSION: Significant but weak positive association was found between the normative and subjective orthodontic treatment needs, indicating a lack of understanding of the nature of malocclusion and its consequences. Thus, promoting further knowledge and awareness of malocclusion are indicated.