A recessed down lighting system having an adjustable retaining bracket. The adjustable retaining bracket facilitates attachment of a reflector to ceilings, walls, or the like of variable thicknesses. The recessed down lighting system may be installed in locations having reduced overhead space above the ceiling or where minimal lateral clearance is available behind the ceiling. The retaining bracket and fastener can be installed and vertically adjusted through the open end of the reflector to secure the reflector to the ceiling.