Several studies have been conducted on direct leaching of zinc sulfide concentrate, in the recent years, though the results of these studies are not in balance with the industrial condition. Hence, the aim of the current investigation was to study direct leaching of the Angouran zinc sulfide concentrate using a tubular reactor on a pilot scale. The volume and height of the reactor were 440 dm3 and 9 m, respectively and sphalerite was dissolved under hydrostatic pressure of the reactor. The ferrous sulfate concentration of the solution plays a key role in the process and sphalerite oxidation by regenerated ferric sulfate has been proposed as main dissolution mechanism in the direct leaching process. The working parameters such as ferrous sulfate, sulfuric acid and air flow rate, zinc sulfate initial concentration and particle size were analyzed in this study. Due to the scale effect and higher rate and volume of reactor in comparison with laboratory-scale experiments, reached data are more reliable to use in industrial applications. The zinc conversion percent increased as the ferric sulfate and sulfuric acid concentration was increased, but the criterion was decreased with an increscent of zinc sulfate initial concentration and the particle size. About 86% of zinc was recovered at temperature 368 K (95 °C), 0.4 mol dm-3 ferrous sulfate concentrations, 0.25 mol dm-3 sulfuric acid, and air flow rate of 0.41 dm3air dm-3slu min-1.