The invention concerns a hybrid drive train comprising a heat engine (2), at least one first electrical machine (31) and at least a second electrical machine (32) each including a stator and a rotor, a battery (BAT) connected to the first and second electrical machines (31, 32), and a controlling member (5) for controlling the charge or discharge of the battery (BAT), the heat engine (2) and the first and second electrical machines (31, 32). The invention is characterized in that the first electrical machine (31) is arranged between the transmission member (4) and one (7D) of the driven wheels (7G, 7D), and in that the second electrical machine (32) is arranged inside the heat engine (2), the rotor of the second electrical machine (32) being fixed on a crank web and its stator (34) being fixed in the housing (36) of the heat engine (2).