Information concerning geologic features of pitchblende veins throughout the world has been assembled. Thirteen of these deposits are described briefly and their features are summarized and classified.Several of the deposits belong to Bastin's (2) nickel-cobalt-native silver type and are dominantly in metamorphic host rocks. The remaining deposits have certain features in common, namely: simple mineralogy, pyrite and/or galena as the representative metallic minerals, silica or fluorite gangue, and granitic or monzonitic host rock. These deposits appear to constitute a second type of pitchblende-bearing deposits, which is described as the siliceous-pyrite-galena type.Three uranium metallogenic epochs are recognized: those of Precambrian age in Africa and the Canadian Shield, late Paleozoic in Europe, and late Mesozoic-early Tertiary in the Cordillera of North and South America. Other features common to many of the described deposits include the variable paragenetic position of pitchblende, the controlling influence of tensional fractures on pitchblende deposition, and the widespread association of pitchblende with hematitic alteration.