Background: Marfan Syndrome (MFS) is a life-threatening connective tissue disorder with an often elusive diagnosis. Diagnosis is based on clinical findings outlined in the Ghent criteria which define hallmark features of the syndrome in the cardiovascular, ocular, and skeletal systems. The morbidity and mortality associated with MFS warrant timely diagnosis and intervention that can improve long-term prognosis. Previous research has highlighted the diagnostic value of craniofacial features in diagnosis; accordingly the aim of this study was to investigate craniofacial and dentoalveolar features in child, adolescent, and young adult patients with MFS. We hypothesized that a distinct craniofacial morphology exists for patients with MFS that can be described quantitatively and qualitatively. Methods: Twenty subjects with a positive diagnosis of MFS were recruited for this study (N=20). Craniofacial anthropometric measurements were made on each subject and compared to established norms of age- and sex-matched controls. The test measurements were compared to the control measurements by calculating a z-score for each test measurement; the measurements were categorized as normal or abnormal based on z-score. Lateral and frontal photographs were obtained to make qualitative assessments and describe facial features of subjects, and a clinical exam was completed to document occlusal relationships. Biometric and demographic information were obtained using a questionnaire. Results: The subjects were primarily female (60%) ranging in age between 4 to 25 years (mean age 10.7±6.0years). Comparison of craniofacial measurements revealed that for 9 of the 12 measurements, ≥65% of the study population had a z-score of ±2 and fell within the normal range for facial dimension. For 3 of the 12 measurements, over half of the subjects fell outside of the normal range (z-score <-2 or >2) for facial dimension. Assessment of the frontal and lateral photographs revealed the most prevalent facial features were retrognathia (54%) and down-slanting palpebral fissures (62%). For occlusal relationships, 55% of subjects had a Class I molar relationship, 40% a Class II relationship, and 5% a Class III relationship. Conclusion: Our data suggests there are quantitative differences in the facial morphology of patients with MFS when compared to a control population.