One-month and 6-month prevalence and symptom profiles of panic disorder from six cross-national epidemiologic studies are reported. These studies were conducted at five sites in the United States, Puerto Rico, Germany, Lebanon, Korea, and New Zealand. Results show that the 1 - and 6-month rates were consistent in the five sites in the United States and in other countries. There was a predominance of females in the rates of panic disorder in most countries. Palpitations and trembling were prevalent in 60% or more persons with panic disorder at all sites. The results show that panic disorder is present with similar phenomenology in diverse cultures that have been studied