A process for depolymerizing waste plastic material and producing a pyrolytic product, wherein said process comprises the following steps: (a) feeding a mixture comprising waste plastic materials, in an oxygen-free atmosphere, into a feeding system comprising at least one screw extruder, which is heated at melting temperature of said plastic material; (b) feeding the molten plastic material coming from the extruder into a first depolymerization reactor, which is a continuously stirred tank reactor maintained at a temperature ranging from 280 to 600°C and operated under a pressure ranging from 1 to 10 barg in which depolymerization takes place thereby forming a gaseous effluent and a liquid effluent; (c) direct at least a portion of the liquid effluent produced in the first reactor to a char handling section and feeding the gaseous effluent from reactor to a condensation unit from which a gaseous stream and a liquid stream are generated; (d) direct the gaseous stream from the first condensation unit to a second condensation unit working at temperature lower than the said first condensation unit and direct the liquid stream coming from the condensation unit to a second depolymerization reactor, which is a continuously stirred tank reactor maintained at a temperature ranging from 280 to 600°C and operated under a pressure ranging from 1 to 10 barg in which depolymerization takes place thereby forming a gaseous effluent and a liquid effluent; (e) withdrawing the gaseous effluent from said depolymerization reactor and feeding it to the second condensation unit and recycle at least a portion of the liquid effluent coming from depolymerization reactor to the first depolymerization reactor; said process being further characterized by the fact that a pyrolytic product is recovered from condensation unit and that at least one of the depolymerization reactors and operates in the presence of a depolymerization catalyst. (a) feeding a mixture comprising waste plastic materials, in an oxygen-free atmosphere, into a feeding system comprising at least one screw extruder, which is heated at melting temperature of said plastic material; (b) feeding the molten plastic material coming from the extruder into a first depolymerization reactor, which is a continuously stirred tank reactor maintained at a temperature ranging from 280 to 600°C and operated under a pressure ranging from 1 to 10 barg in which depolymerization takes place thereby forming a gaseous effluent and a liquid effluent; (c) direct at least a portion of the liquid effluent produced in the first reactor to a char handling section and feeding the gaseous effluent from reactor to a condensation unit from which a gaseous stream and a liquid stream are generated; (d) direct the gaseous stream from the first condensation unit to a second condensation unit working at temperature lower than the said first condensation unit and direct the liquid stream coming from the condensation unit to a second depolymerization reactor, which is a continuously stirred tank reactor maintained at a temperature ranging from 280 to 600°C and operated under a pressure ranging from 1 to 10 barg in which depolymerization takes place thereby forming a gaseous effluent and a liquid effluent; (e) withdrawing the gaseous effluent from said depolymerization reactor and feeding it to the second condensation unit and recycle at least a portion of the liquid effluent coming from depolymerization reactor to the first depolymerization reactor;