Example embodiments provide lighting fixture mounting kits for mounting a flat panel lighting fixture to a mounting surface. One mounting kit comprises a mounting frame and a lighting fixture. When the mounting frame is secured to the mounting surface, a junction box is accessible therethrough. The mounting frame and lighting fixture are shaped for engagement and attachment to one another. Another mounting kit comprises a mounting plate and a lighting fixture. The mounting plate may comprise indexing tabs for alignment with corresponding indexing slots of the lighting fixture and extending outwardly from a plate portion of the mounting plate. The lighting fixture may comprise a back portion having therein one or more indexing slots for receiving an indexing tab therein. Insertion of the indexing tab into the indexing slot guides the engagement of the lighting fixture with the mounting plate.