Abstract A new extraction method by pressure leaching has been applied to recover nickel from limonite type laterites. Pressure leaching was carried out with aqueous solutions of polyamines at temperatures above 180°C. During leaching goethite minerals containing most of the nickel in high-iron laterites are converted to hematite in alkaline solutions and nickel which is liberated from the goethite lattice is extracted by chelate-complex formation with polyamines. Pretreatment of the ores prior to leaching is not necessary. Recovery of nickel from the resulting pregnant solutions can be realized by solvent extraction methods. The only reagent consumed by this process is lime. Detailed studies were conducted to investigate the leaching mechanism which was found to be dependent both on the ore characteristics and on the chemistry of the polyamine containing leach solutions.