A process for producing 1,1,3,3-tetrachloropropene, comprising: preparing a reaction mixture comprising the isomers 1,1,1,3,3-pentachloropropane as the first isomer and 1,1,1,2,3-pentachloropropane as the second isomer, comprising chlorinating the 1,1,1,3-tetrachloropropane starting material with molecular chlorine in a chlorination zone, wherein the concentration of the 1,1,1,3-tetrachloropropane starting material is controlled such that conversion of 1,1,1,3-tetrachloropropane to the resulting isomers, represented by the molar ratio of 1,1,1,3-tetrachloropropane : the resulting isomers present in the chlorination zone does not exceed 40:60, the molecular chlorine being fed to the chlorination zone in an amount of 15 to 45 % by moles of 1,1,1,3-tetrachloropropane, subjecting the reaction mixture to one or more distillation steps to produce a plurality of the resulting isomers stream, one or more single resulting isomer streams and optionally a 1,1,1,3-tetrachloropropane starting material stream, subjecting the plurality of the resulting isomers stream to a selective dehydrochlorination step in which the first isomer is converted to 1,1,3,3-tetrachloropropene without the substantial dehydrochlorination of the second isomer, said selective dehydrochlorination being carried out in the liquid phase using a metal-containing catalyst comprising elemental iron and / or FeCl 3 , the dehydrochlorination zone being free of alkaline hydroxide, the residence time of the reaction mixture in the dehydrochlorination zone ranging from 0.1 to 5 hours, the operating temperature in the dehydrochlorination zone being from 50 to 150°C, and obtaining a stream rich in or consisting of 1,1,3,3-tetrachloropropene from the mixture prepared in the dehydrochlorination step. preparing a reaction mixture comprising the isomers 1,1,1,3,3-pentachloropropane as the first isomer and 1,1,1,2,3-pentachloropropane as the second isomer, comprising chlorinating the 1,1,1,3-tetrachloropropane starting material with molecular chlorine in a chlorination zone, wherein the concentration of the 1,1,1,3-tetrachloropropane starting material is controlled such that conversion of 1,1,1,3-tetrachloropropane to the resulting isomers, represented by the molar ratio of 1,1,1,3-tetrachloropropane : the resulting isomers present in the chlorination zone does not exceed 40:60, the molecular chlorine being fed to the chlorination zone in an amount of 15 to 45 % by moles of 1,1,1,3-tetrachloropropane, subjecting the reaction mixture to one or more distillation steps to produce a plurality of the resulting isomers stream, one or more single resulting isomer streams and optionally a 1,1,1,3-tetrachloropropane starting material stream, subjecting the plurality of the resulting isomers stream to a selective dehydrochlorination step in which the first isomer is converted to 1,1,3,3-tetrachloropropene without the substantial dehydrochlorination of the second isomer, said selective dehydrochlorination being carried out in the liquid phase using a metal-containing catalyst comprising elemental iron and / or FeCl 3 , the dehydrochlorination zone being free of alkaline hydroxide, the residence time of the reaction mixture in the dehydrochlorination zone ranging from 0.1 to 5 hours, the operating temperature in the dehydrochlorination zone being from 50 to 150°C, and obtaining a stream rich in or consisting of 1,1,3,3-tetrachloropropene from the mixture prepared in the dehydrochlorination step. <EOS>