A machine to manufacture cartridges for electronic cigarettes comprising a casing made of plastic material having a microperforated bottom wall and a side wall and containing a quantity of powdered tobacco on top of which a portion of filtering material is arranged; the manufacturing machine comprises: a feeding conveyor which feeds a plurality of empty casings in correspondence to a collecting station; a first drum rotating at a predetermined pitch around its own vertical rotation axis, which receives an orderly mass of empty casings from the feeding conveyor, in correspondence to the collecting station, and feeds them through a succession of processing stations (FS, WRS, FRS, CDS); wherein the first drum is provided with a plurality of peripheral first seats, each designed to receive a respective casing, and which are divided into groups comprising the same number of first seats; in which the casings of the first seats of a same group are simultaneously subjected to the processes in correspondence to the succession of processing stations (FS, WRS, FRS, CDS); the manufacturing machine is characterized in that the machine comprises a second drum rotating at a predetermined pitch around its own vertical rotation axis, which is designed to receive from the first drum the casings containing a quantity of powdered tobacco on top of which a portion of filtering material is arranged in correspondence to a loading/unloading station in which the first drum partially overlaps the second drum and the second drum is provided with a number of second seats obtained on the periphery of the second drum itself and which are divided into groups, each group having a number of second seats which is equal to the number of first seats of the groups of the first drum. a feeding conveyor which feeds a plurality of empty casings in correspondence to a collecting station; a first drum rotating at a predetermined pitch around its own vertical rotation axis, which receives an orderly mass of empty casings from the feeding conveyor, in correspondence to the collecting station, and feeds them through a succession of processing stations (FS, WRS, FRS, CDS); wherein the first drum is provided with a plurality of peripheral first seats, each designed to receive a respective casing, and which are divided into groups comprising the same number of first seats; in which the casings of the first seats of a same group are simultaneously subjected to the processes in correspondence to the succession of processing stations (FS, WRS, FRS, CDS); the manufacturing machine is characterized in that the machine comprises a second drum rotating at a predetermined pitch around its own vertical rotation axis, which is designed to receive from the first drum the casings containing a quantity of powdered tobacco on top of which a portion of filtering material is arranged in correspondence to a loading/unloading station in which the first drum partially overlaps the second drum and the second drum is provided with a number of second seats obtained on the periphery of the second drum itself and which are divided into groups, each group having a number of second seats which is equal to the number of first seats of the groups of the first drum.