OBJECTIVES: The objective of this study is to clarify the clinical characteristics of late-onset panic disorder (PD) compared to early-onset PD in symptoms frequency, severity, and quality of life. METHODS: 516 patients with PD were included in this study. Patients with PD onset at 60 or after were grouped (late-onset), and compared with the group with onset at 20 or earlier (early-onset). The following instruments were applied : Beck Depression Inventory, Beck Anxiety Inventory, Panic Disorder Severity Scale, Albany Panic and Phobia Questionnaire, Anxiety Sensitivity Inventory-Revised, and Medical Outcomes Study 36-item Short-Form Health Survey. SPSS version 21.0 was used for statistical analysis. RESULTS: Late-onset PD was 4.84% of all PD patients, and the mean age was 64.68+/-4.36 years. Late-onset PD exhibited fewer panic symptoms and scored lower on most scales assessing clinical severity. However, the panic-related symptoms severity showed significant negative correlations with scores of quality of life, especially in physical functioning subscale, among the late-onset PD patients. CONCLUSION: These findings suggest that less severe panic symptoms may contribute to underdiagnosing PD in this elderly population. However, the panic-related symptoms severity plays an important role in quality of life among the late-onset PD patients. It suggests to implement specific strategies considering the age at onset in clinical approach among patients with PD.