A linear drive comprising a transmission housing and an electric motor which is connected thereto and which drives a mounted shaft which in turn drives a worm which meshes with a worm gear which is non-rotatably connected to a spindle on which runs a spindle nut, arranged displaceably in a guide tube. Provided between the guide tube and the spindle nut to ensure correct rotary angle orientation of the spindle nut, in relation to the guide tube are inner barsa and complementary guide grooves. To simplify machine-assisted mounting of the spindle nut, in the guide tube there are provided positional orientation means which implement correct rotary angle orientation of the spindle nut, upon insertion thereof into the guide tube in the push-in direction.