Nickel extraction from hazardous waste by sulphuric acid leaching has been investigated. This study was performed to assess the effects of different parameters such as reaction time, acid concentrations, solid-liquid ratio, particle size, stirring speed and reaction temperature on nickel extraction from zinc plant residue, with the aim of recycling this waste and reducing its environmental impact. It was shown that the nickel extraction increased with increasing reaction time, acid concentration and temperature, and decreasing solid:liquid ratio and particle size. Leaching residues were subjected to chemical analysis, XRD and SEM studies, and the results indicated that it is possible to extract more than 96% nickel content by optimization of leaching conditions. These results provided important data on the recovery of nickel from toxic hazardous waste, and leaching is a suitable method for this waste management. The results also showed that this waste can be used as a secondary resource for nickel extraction.