A method of fabricating a CMOS image sensor is provided, in which a trapezoidal microlens pattern profile is formed to facilitate reflowing the microlens pattern and by which a curvature of the microlens may be enhanced to raise its light-condensing efficiency. The method includes forming a plurality of photodiodes on a semiconductor substrate; forming an insulating interlayer on the semiconductor substrate including the photodiodes; forming a protective layer on the insulating interlayer; forming a plurality of color filters corresponding to the photodiodes; forming a top coating layer on the color filters; forming a microlens pattern on the top coating layer; and forming a plurality of microlenses by reflowing the microlens pattern.