The use of diagnostic sonography allows determination of the prevalence of gallstones in a representative sample of the general population. The objective of this article is to review the reports of sonographically based studies of gallstone prevalence in the world literature. All available published epidemiologic studies on the prevalence of cholecystolithiasis as determined by diagnostic sonography are summarized. The sonographically based studies published to date confirm that there are significant regional differences in the prevalence of gallstones. Certain risk factors, notably age and heredity, are present worldwide.