Coronavirus disease 2019 (COVID-19) is a pandemic outbreak increasing several psychological distress, such as anxiety and phobia, and may affect patients with anxiety disorders. A scale has been recently designed to assess COVID-19-related phobic reactions named the COVID-19 Phobia Scale (C19P-S). The present study aimed to evaluate factor structure, reliability, and validity of the Persian version of the C19P-S (Persian-C19P-S) in patients with anxiety disorders and to compare COVID-19-related phobia among these patients. Three hundred patients with anxiety disorders completed the Persian-C19P-S and other scales assessing anxiety traits (e.g., the Short Health Anxiety Inventory (SHAI), the Health Concerns Questionnaire-54 (HCQ-54), and the Patient Health Questionnaire-4 (PHQ-4)) and COVID-19-related distress (e.g., the COVID Stress Scales (CSS) and the Fear of COVID-19 Scale (FCV-19)). The results showed that the Persian-C19P-S replicated the four-factor structure of the original C19P-S. Internal consistency and test-retest reliability coefficients evidenced the reliability of the scale. The validity of the scale (convergent and discriminant validity) was confirmed. Patients who had generalized anxiety and panic disorders showed higher phobic reactions related to COVID-19 than those with social anxiety disorder and specific phobia. This study indicates that the Persian version of the C19P-S is a valid scale to be used in Iranian patients with anxiety disorders to evaluate COVID-19-related phobia. Moreover, COVID-19-related phobic reactions are higher in some specific types of anxiety disorders.