A trenching attachment for selective attachment to a working machine features a frame arranged for selective connection to the working machine, an internal combustion engine mounted to the frame and a boom assembly connected to the frame and having a trencher chain installed thereon. The internal combustion engine is operatively connected to the trenching chain to facilitate driving thereof. Having its own dedicated engine, the trenching attachment is less dependent on the power take-off system of the working machine than a conventional trenching attachment that uses a hydraulic motor to power the trencher chain and relies exclusively on delivery of hydraulic fluid from the working machine for operation.