The gutter foam filter elements are generally triangular, four-foot lengths of flexible plastic open-cell foam material placed in and extending the full length of a conventional "K" type or similar roof gutter. The foam filter elements may be inserted within the gutter below gutter spikes. The foam material is an open-pore polyether foam of 10 20 cells per square inch which allows rainwater to travel through the filter while excluding leaves. The foam is generally in the form of a right triangle and so disposed in the gutter as to have one side extending along the back of the gutter and the other side of the triangle spanning the open space across the upper open portion of the gutter. The sloped wall defines a void in the lower front portion of the gutter for rainwater flow to a downspout. The lower corner of the element is truncated forming a lower support wall.