Abstract: A convertible combined stroller and trailer which can be changed from a stroller mode to a trailer mode and vice versa. When the vehicle is in either the stroller mode or trailer mode it includes a flexible seat for one or more passenger. When used in a stroller mode, rear wheels are attached to the opposite sides of the rear of the frame at a position called "Position S" and front wheels are attached to the opposite sides of the front of the frame. At this position the load on the frame is distributed evenly on the rear wheels and on the front wheel. When the vehicle is in a trailer mode the front wheels are removed, the rear wheels are moved from the "Position S" to a position forward and upward on the sides of the frame called "Position T", and one end of a tow bar is attached to the front of the vehicle frame. Another end of the tow bar is attached to the rear of a towing vehicle, such as a bicycle frame.