A guide assembly of a self-propelled type for an endoscope including an elongated tube for entry in a body cavity is provided. First and second self-propelled units are mounted on a steering device of the elongated tube in an axial direction thereof, for contacting a wall of the body cavity for propulsion. The first and second self-propelled units include respectively first and second driving devices, actuated with force by an external drive source, for converting the force for the propulsion. The first self-propelled unit includes a first torque coil structure for transmitting the force from the drive source to the first driving device. The second self-propelled unit includes a second torque coil structure for transmitting the force from the drive source to the second driving device discretely from the first torque coil structure. The first self-propelled unit is fixedly mounted on the steering device.
