Abstract: Apparatus to provide a mountable worksurface for the operation of a computer mouse adapted to be attached to a computer workarea comprising a first clamp element slidably attached to a substantially flat rectangular mouse worksurface and locking means to lock said first clamp element at a predetermined position in relation to said mouse worksurface whereby said first clamp element is adapted to clamp the upper portion of a computer workarea with said mouse worksurface positioned horizontally at a selected off-set to the computer workarea; a pair of extension arms attached to and extending below opposing sides of said mouse worksurface, adjacent to the side incorporating said first clamp element; each extension arm provided with a channel for slidably receiving a second clamp element, said second clamp element adapted to be positioned to engage the underside of said computer workarea inward from the edge thereof, and locking means to lock each said second clamp element to its corresponding extension arm at a p