The invention provides a swing-type power unit integrally including an engine and a transmission, which is capable of facilitating the manufacture, assembly and handling of the engine, and allowing free combination of the engine and transmission thereby enhancing the general versatility thereof. To achieve this, a swing-type power unit P integrally includes an engine E and a transmission T for transmitting a drive force of the engine E to a drive wheel Wr, and is swingably supported by a body frame. An engine block is divided into first and second engine blocks 32 and 33 which are disposed on the front and rear sides with a crank shaft 31 put therebetween, respectively. Casings 37 and 38 of the belt-type continuously variable transmission T are removably connected to the left side surfaces of the first and second engine blocks 32 and 33 with bolts 74 and 75.