The Kuh-e-Surmeh Zn–Pb deposit is hosted by Upper Permian carbonate platform in the Zagros Fold Belt of southwestern Iran. The orebody is characterized by massive, vein, and banded textures. It is mostly composed of sphalerite, galena, and pyrite accompanied with minor barite. Homogenization temperatures of fluid inclusions in sphalerite and barite range from 94.7° to 200.0 °C and 93.6° to 198.0 °C, respectively. Fluid salinities of sphalerite- and barite-hosted inclusions vary from 8.1 to 21.3 wt% NaCl equiv. and 10.5 to 22.6 wt% NaCl equiv., respectively. The δ34S values of barite range from 11.2 to 11.9‰, similar to those of gypsum of the Nar Member (+10.9 to +11.7‰) in the Upper Permian sedimentary strata and different from the δ34S values of Jahani Salt Dome gypsum (+29.1 to +30.5‰), indicating that sulfur was derived from the Upper Permian evaporites. The δ34S values of galena and sphalerite range from −1.7 to −15.4‰, compatible with bacterial sulfate reduction (BSR) of the Upper Permian evaporites. The Pb isotopic compositions of galena yield 206Pb/204Pb ratios from 17.942 to 18.340, 207Pb/204Pb ratios from 15.649 to 15.744, and 208Pb/204Pb ratios from 38.186 to 38.458, indicating an upper crustal lead source.Based on ore textures, fluid inclusions, isotope data, and geochemical compositions of sulfide minerals, the Kuh-e-Surmeh sulfide mineralization is believed to have precipitated from low-temperature sedimentary basin brines and should be classified as a Mississippi Valley-type deposit in a salt diapir environment. Mineralization is the result of mixing of hypogene metalliferous fluids with more dilute, H2S-rich fluids during Miocene–Pliocene compression associated with the Zagros Orogeny.