A computer component mounting system includes two mounting frames (30) attached to two side panels (52) of a chassis (50) respectively, and a mounting bracket (10) having a main portion (12) for attaching computer components (100) such as fans (100) thereto, and two mounting portions (13) at opposite ends of the main portion. Each mounting frame includes a base plate (32) forming a positioning plate (322), and two side plates (36) each forming an oblique guide plate (362). A locking slot (364) is defined in each side plate and adjoining guide plate. Each mounting portion includes two locking tabs (140, 160) engaging in the locking slots of a corresponding mounting frame, and a positioning tab (15) joined to the positioning plate of the corresponding mounting frame to thereby secure the mounting bracket to the mounting frames. The fans are thus secured within the chassis.