Abstract: A mounting assembly for mounting a fire sprinkler head in a suspended ceiling supported by a grid of suspended rails includes a tubular sprinkler reducer, a latitudinal supporting member, and a mounting bracket. The tubular sprinkler reducer includes an upper end connectable to a sprinkler supply pipe and a lower end connectable to a sprinkler head. The latitudinal supporting member includes a supporting bracket on each end for attachment to the suspended rails. The mounting bracket is located around an intermediate region of the sprinkler reducer and has first and second spaced-apart flanges extending to one side that define between them a horizontally-extending mounting channel into which the latitudinal supporting member can be inserted. The mounting bracket further includes at least one closure member for closing the mounting channel after the latitudinal supporting member is inserted therein.