Recent epidemiological studies have consistently shown that panic disorder, according to DSM-III, occurs in adults with a lifetime prevalence of about 2% and a 6-month prevalence of about 1.2%. Panic attacks are relatively common, with a lifetime rate of about 9%. Being female and divorced and separated is associated with higher prevalence of panic disorder. The hazard rates for panic disorder were highest between the ages of 25 and 34 years for females and between the ages of 30 and 44 years for males. Panic disorder frequently co-occurs with other anxiety disorders as well as with a wide range of mental disorders such as depression and substance use disorder. Based on few epidemiological studies, panic disorder has been found to have a chronic course with rare complete remission. Subjects with panic disorder were at an increased risk of social impairment, not getting along with their partners, as well as being financially dependent, and were likely to report fair or poor global physical health, and emotional health. Cases with panic disorder had the most severe psychosocial impairment and the worst outcome as compared to other anxiety disorders. Moreover, they are high users of all types of medical services, including mental health and general medical providers. Although recent epidemiological data, with its improved methodology, have considerably increased our knowledge concerning panic attack, panic disorder and agoraphobia, there are still major questions concerning the etiology, natural history, prevention, or control of panic disorder that need to be answered. Furthermore, since panic disorder has been considered as developing in stages, our current epidemiological knowledge cannot tell us in sufficient detail about the specific role of suggested risk factors in the development of panic disorder through its various stages.