There are significant similarities and differences between the copper and zinc-lead deposits of the Mount Isa region of Australia and the Tsumeb region of Namibia. Copper deposits are hosted by brecciated and altered sedimentary (mostly carbonate) rocks and are breccia-filling, vein, stockwork or replacement deposits. They have broadly similar alteration assemblages, dominated by quartz, carbonate, iron sulphide and iron oxides, but with varying proportions of white mica and chlorite. Features common to both regions include the likely derivation of copper from basalts, the presence of crustal sulphur at the site of deposition, the probable derivation of ore-bearing fluid from evaporites, the regional flow of metal-bearing brines, the temperatures of ore deposition, and the lack of any spatial or temporal association with igneous intrusions. The onset of deformation may have been a driving force for the movement of hydrothermal fluid. Differences include the timing of copper mineralisation relative to folding (at least at the site of ore deposition), the relative importance of stratigraphic versus structural controls on regional fluid flow, the proportion of mineralisation hosted by syndeformational sites versus early-formed (e.g. karst) structures, and the geometry of mineralised sites. A broad model that encompasses all features of both regions is used to suggest new exploration possibilities in the Mount Isa and Tsumeb areas.