The invention relates to a hybrid drive assembly of a motor vehicle, comprising: a main transmission (2), which has a transmission input shaft (4) and a transmission housing; an electric machine (5), which can be operated as a motor and as a generator, which has a rotor (5b), and is arranged on the input side with respect to the main transmission (2); and a planetary gearset (6), which has a sun gear (7), a planetary carrier (8), and a ring gear (9), wherein the planetary gearset (6) is connected to the rotor (5) by means of the sun gear (7) on one side and is connected to the transmission input shaft (4) on the other side. According to the invention the planetary carrier (8) is connected to the transmission input shaft (4) in a rotationally fixed manner and the ring gear (9) is arranged in a housing-fixed manner.