Abstract: A computer system unit which includes an acoustic dampening cooling fan shroud panel mounted on a rear surface thereof. The computer system unit is generally rectangular, encloses an electronic component package and includes a front panel and a pair of generally parallel side panels. An intermediate rear panel, generally parallel to the front panel, mounts one or more cooling fans which draw air through the generally rectangular unit. A cooling fan shroud panel which includes an acoustic noise reduction lining is then mounted to the intermediate rear panel. The cooling fan shroud panel includes an aperture for ventilation which is displaced from the mounting position of the cooling fans such that acoustic noise resultant from cooling fan operation is minimized. The aperture within the cooling fan shroud panel extends into at least one surface thereof which is not parallel to either the side panel or the intermediate rear panel wherein ventilation is substantially unobstructed by adjacent vertical surfaces.