A five-year field study evaluated 42 sunflower (Helianthus annuus L.) accessions, 25 breeding lines, and 40 interspecific crosses for resistance to infestation and damage from larval feeding by naturally occurring populations of the sunflower moth, Homoeosoma electellum (Hulst) (Lepidoptera: Pyralidae). Accessions PI 175728 and PI 307946 had less than 3% feeding damage per head in all three years they were tested. Some interspecific crosses showed evidence of resistance; PAR 1673-1 had less than 2% seed damage in 2002 and 2003 and less than 3% in 2005. PRA PRA 1142 sustained less than 3% seed damage and STR 1622-1 had less than 2% seed damage in three years of trials. Breeding lines with potential resistance included 01-4068-2, which had the least amount of seed damage per head in 2002 (<1%) and in 2003 averaged only 2% damage. Line 01-4080-1, with less than 1% damage in 2002 and in 2003, was the least damaged entry in these evaluations. Hybrid ‘894’ was included as a standard check; however, it consistently had among the lowest average seed damage from H. electellum feeding. Our investigation showed the potential for developing resistant genotypes for the sunflower moth to reduce seed feeding injury and to prevent yield losses for sunflower producers. The development of germplasm with host plant resistance would provide another tool in an integrated pest management approach for H. electellum. Additional effort is in progress to use the identified lines to introgress resistance genes into cultivated sunflower through conventional breeding facilitated by marker-assisted selection.