Abstract: An improved coupling guard for enclosing rotating couplings, shafts and other devices with the improvement comprising an interlocking closure consisting of a retainer element, a retained element and a resilient gasket substantially between the retainer and the retained elements. The improved coupling guard provides a substantially leakproof enclosure that is easily assembled and disassembled. In a preferred embodiment of the invention, the guard comprises two or more semi-cylindrical shell portions that cooperate to form a substantially cylindrical enclosure and that are joined by use of the interlocking closures. In the closures, the gasket is adapted to both seal the closure against leakage and to resiliently bias the retained element into retaining engagement with the retainer element.