Adenovirus (AV) types 1, 2, and 5, isolated from about 480 patients from 1960 to 1985, most from the United States and Central Europe, were studied by DNA restriction analysis with the endonucleases BamHI, BglII, BstEII, EcoRI, HindIII, KpnI, and SmaI and compared with the respective prototypes. All different fragment patterns are presented as schematic drawings and their distribution on the genome types was analyzed. Prototype-like strains were isolated in all three types. AV2 exceeded AV1 and AV5 in its genetic variability. Among the many genome types found (36, 61, and 35 for AV1, 2, and 5 respectively), only one or few of each type prevailed, whereas many others were found only once. The temporal and geographic distribution of the genome types is presented.