[en] Vein-type uranium deposits in Portugal demonstrate a broad temporal and physical spectrum from intragranitic hydrothermal jasper-type veins formed at moderately high temperatures, through lower temperature quartz veins and peribatholithic disseminated mineralization of 'Iberian-type', to undoubted supergene enrichments in surface-related planar traps such as weathered basic dikes. All appear to be in close spatial relationship to 'fertile' Hercynian granites in which uraninite of low thorium content is the main contributor to the enriched uranium levels. The availability of this large source of labile uranium, a pervasive fracture network and a series of tectonic and intrusive events which could generate hydrothermal circulation, allow several alternative genetic models for the mineralization. It now appears that the classic hydrothermal pitchblende veins within the granite are most likely of late-Hercynian age. Many of the mineralogical and depositional characteristics of the lower temperature 'Iberian-type' deposits suggest a temporal continuity to this mineralization but, as yet, no supporting age data are available. It is conceded, therefore, that a considerable time-gap could occur between the two episodes, with the peribatholithic mineralization resulting from later rejuvenation of the hydrothermal convective system. (author)