A method of recovering ammonium sulphate from a gas stream produced in a urea plant, and in particular by a solidification unit of the urea plant, comprising the steps of: - treating a gas stream from a solidification unit in a scrubber connected to the solidification unit, to remove ammonia from said gas stream by reaction with sulphuric acid with formation of a water and ammonium sulphate solution; - drawing the ammonium sulphate solution off from the scrubber; - mixing the ammonium sulphate solution with a low-concentration urea solution produced in the urea plant, and removing water in an evaporator, to form a urea-ammonium sulphate eutectic; the eutectic having a 30-60% by weight ammonium sulphate concentration, a melt temperature of 121-150°C and a water content less than 1%; - recirculating part of said eutectic from the evaporator to the top of the evaporator, and mixing the rest with high-concentration urea melt produced by the urea plant; - feeding said eutectic, mixed with high-concentration urea melt produced by the urea plant, to the solidification unit; wherein the low-concentration urea solution fed to the evaporator has a lower concentration than the high-concentration urea melt mixed with the eutectic; and wherein the ammonium sulphate solution formed in the scrubber is fed to the evaporator where the urea-ammonium sulphate eutectic is formed; the high-concentration urea melt having a flow rate of 100-200 times that of the urea-ammonium sulphate eutectic from the evaporator and the final mixture resulting from mixing the high-concentration urea melt and the urea-ammonium sulphate eutectic contains less than 0.5% by weight of ammonium sulphate; and wherein the low-concentration urea solution has a concentration of less than 95% by weight. - treating a gas stream from a solidification unit in a scrubber connected to the solidification unit, to remove ammonia from said gas stream by reaction with sulphuric acid with formation of a water and ammonium sulphate solution; - drawing the ammonium sulphate solution off from the scrubber; - mixing the ammonium sulphate solution with a low-concentration urea solution produced in the urea plant, and removing water in an evaporator, to form a urea-ammonium sulphate eutectic; the eutectic having a 30-60% by weight ammonium sulphate concentration, a melt temperature of 121-150°C and a water content less than 1%; - recirculating part of said eutectic from the evaporator to the top of the evaporator, and mixing the rest with high-concentration urea melt produced by the urea plant; - feeding said eutectic, mixed with high-concentration urea melt produced by the urea plant, to the solidification unit; wherein the low-concentration urea solution fed to the evaporator has a lower concentration than the high-concentration urea melt mixed with the eutectic; and wherein the ammonium sulphate solution formed in the scrubber is fed to the evaporator where the urea-ammonium sulphate eutectic is formed; the high-concentration urea melt having a flow rate of 100-200 times that of the urea-ammonium sulphate eutectic from the evaporator and the final mixture resulting from mixing the high-concentration urea melt and the urea-ammonium sulphate eutectic contains less than 0.5% by weight of ammonium sulphate; and wherein the low-concentration urea solution has a concentration of less than 95% by weight.