Uraninite occurs as rare accessory mineral in barren and beryl–columbite granitic pegmatites genetically related to Variscan S- and I-type granitic rocks from the Tatric Unit of the Western Carpathians, Slovakia. Uraninite forms individual euhedral crystals in alkali feldspars and muscovite (Prašivá Massif, Nízke Tatry Mountains) or more frequently numerous tiny (up to 15 µm in size) anhedral to subhedral inclusions in host metamict zircon (Žiar and Považský Inovec Mts.). Textural relationships indicate primary magmatic origin of individual euhedral uraninite crystals, but a subsolidus, secondary formation of uraninite inclusions in zircon by alteration processes, including metamictization and fluid-driven dissolution–reprecipitation of host zircon. The SEM-EDX based U–Th–Pb measurements and dating of uraninite were carried out. The primary magmatic uraninite, found in a pegmatite from the Prašivá Massif (Nízke Tatry Mts.), was dated at a weighted average age of 347 ± 5 Ma. Systematically older single grain ages between 380–360 Ma were obtained for uraninite micro-inclusions in zircons in case of four pegmatites from the Považský Inovec Mts. In another pegmatite sample from that area, uraninite inclusions in zircon yielded systematically younger single grain ages between 336 ± 9 Ma and 351±10 Ma (343 ± 4 Ma in average). Uraninite from the Žiar Mts. pegmatite gave very consistent younger average age of 325 ± 5 Ma. The non-conformity of uraninite ages in the Tatric West-Carpathian pegmatites is remarkable. The observed spread of ages would accord with recent geological models that propose a long-lived (at least two-stage) Variscan granitic–pegmatitic activity in the Tatric Unit during the Upper Devonian and the Lower Carboniferous. However, partial leaching and escaping of highly mobile U6+ from uraninite (especially from micrometer-sized inclusions in zircon) could be disturbed the U–Th–Pb system and gave seemingly higher age results. Conversely, partial Pb-loss could have yielded apparently younger uraninite ages. Consequently, the reliability and geological significance of the micro-uraninite ages are difficult to assess at present, and more geochronological data from other pegmatite minerals will be necessary to fully evaluate their significance.