The Betic Cordillera in southern Spain is a complex Alpine fold belt that resulted from the Cretaceous through Cenozoic collision of Africa with Europe. The region is illustrative of one of the characteristics of the Alpine-Mediterranean orogen: the occurrence over a limited area of mineral deposits with a wide variety of host rocks, mineralization ages, and styles. The metamorphic basement in the Betic zone is characterized by a nappe structure of superimposed tectonostratigraphic units and consists of lower Paleozoic to Lower Triassic clastic metasedimentary rocks. This is overlain by Middle to Upper Triassic platform carbonate rocks with abundant strata-bound F-Pb-Zn-(Ba) deposits (e.g., Sierra de Gador, Sierra Alhamilla). Cretaceous to Paleogene subduction-related compression in southeastern Spain was followed by Miocene postcollisional extension and resulted in the formation of the Almeria-Cartagena volcanic belt and widespread hydrothermal activity and associated polymetallic mineralization. Typical Miocene hydrothermal deposits include volcanic-hosted Au (e.g., Rodalquilar) and Ag-rich base metal (e.g., Cabo de Gata, Mazarron) deposits as well as complex polymetallic veins, mantos, and irregular replacement bodies which are hosted by Paleozoic and Mesozoic metamorphic rocks and Neogene sedimentary and volcanic rocks (e.g., Cartagena, Sierra Almagrera, Sierra del Aguilon, Loma de Bas).Lead isotope compositions were measured on sulfide samples from nine ore districts and from representative fresh samples of volcanic and basement rock types of the region. The results have been used to evaluate ore-forming processes in southeastern Spain with emphasis on the sources of metals. During a Late Triassic mineralizing event, Pb was leached from Paleozoic clastic metasedimentary rocks and incorporated in galena in strata-bound F-Pb-Zn-(Ba) deposits ( ²⁰⁶ Pb/ ²⁰⁴ Pb = 18.332 + or - 12, ²⁰⁷Pb/ ²⁰⁴ Pb = 15.672 + or - 12, ²⁰⁸ Pb/ ²⁰⁴ Pb = 38.523 + or - 46). The second episode of mineralization was essentially contemporaneous (late Miocene) throughout the region and did not involve remobilization of less radiogenic Triassic ore Pb. Lead isotope data indicate a dominantly Paleozoic metasedimentary source for polymetallic vein- and manto-type deposits that formed by hydrothermal circulation through the Betic basement, driven by Miocene intrusions ( ²⁰⁶ Pb/ ²⁰⁴ Pb = 18.747 + or - 20, ²⁰⁷ Pb/ ²⁰⁴Pb = 15.685 + or - 9, ²⁰⁸ /Pb/ ²⁰⁴ Pb = 39.026 + or - 37). Lead in Au-(Cu-Te-Sn) ores is isotopically indistinguishable from that of the calc-alkalic volcanic host ( ²⁰⁶ Pb/ ²⁰⁴ Pb = 18.860 + or - 9, ²⁰⁷ Pb/ ²⁰⁴ Pb = 15.686 + or - 8, ²⁰⁸ Pb/ ²⁰⁴ Pb = 38.940 + or - 27). In contrast, the Pb in volcanic-hosted Pb-Zn-Cu-(Ag-Au) veins was derived from Paleozoic metamorphic and Miocene volcanic rocks ( ²⁰⁶ Pb/ ²⁰⁴ Pb = 18.786 + or - 5, ²⁰⁷ Pb/ ²⁰⁴ Pb = 15.686 + or - 2, ²⁰⁸ Pb/ ²⁰⁴ Pb = 38.967 + or - 9).A comparison of the Pb isotope data from southeastern Spain with published data from selected Pb-Zn deposits in southern Europe (including Les Malines, L'Argentiere, and the Alpine, Iglesiente-Sulcis, and Montagne Noire districts) indicates the importance of a metasedimentary basement as a common source of ore Pb.