<p>The Kishan Deposit Is One of the Number of Carbonate-hosted Pb–Zn Occurrences and Deposits Located Within the Esfahan-Malayer Metallogenic Belt (MEMB), Iran. These Deposits Occurred in an Extensional back-arc Basin Attributed To the Oceanic Subduction of the Neo-Tethys or Nain-Baft back-arc Basin. Following the Mineralogical Study and Identifying Three Main Mineralization Stages of the Deposit, Including pre-, Main-, and late-post Stages, the S Isotope Data of Six Galena Samples from the Main Mineralization Stage Were analyzed. The δ34S Data Vary between − 3.76 and − 5.36‰, Which after Temperature Corrections by Fluid Inclusion Microthermometeric Data Gave a Narrow Range of −0.98 to −1.76‰, Consistent with the Sulfide Precipitation from Bacteriogenic sulfur-reduction. Additionally, the Fluid Inclusion Microthermometry of the Primary liquid-vapor Bearing Fluid Inclusions Trapped in the Cogenetic Quartz Veins Exhibited a Homogenization Temperature Range of 140° and 272 °C, Corresponding with the Salinity of 10–22 wt% NaCl Equivalent and Density of 0.9–1.1 g/cm³, Illustrating the Irish-type Characteristic in the Th Versus Salinity diagram, Which Is in Agreement with Bacteriogenic Sulfide Reduction (BSR) Processes. Consequently, the Irish-type Metallogeny of the Kishan Deposit Mostly Involves Intermittent Mixing of the Relatively cool, Dense Brines Modified from Contemporaneous Seawater with the Circulating Principal Ore Fluids Containing Leached Metals from the beneath basement, i.e., Metamorphosed Shale and Sandstone of the Shemshak Formation, as Far as the Sealing of Carbonate Host Rock Porosities Has Resulted in Later Prevailed Veining Mineralization. As a result, the Deposit Exhibits a Three-stage Mineralization Process as Stratabound and stratiform, Proposed for the Irish-type Deposits</p>