A firearm cleaning kit includes a case comprising a first side and a second side joined along a fold line, and a fastener for joining together the first and second side of the case. A tool-holding insert is secured to an interior region of the case. The tool-holding insert includes a plurality of tool cavities and a first firearm cleaning implement removably secured in one of the tool cavities. A module attachment element is affixed to an exterior portion of the case. The firearm cleaning kit further includes a modular kit case including a fastening element releasably secured to the module attachment element of the case. The modular kit case further includes a second firearm cleaning implement removably secured thereto.