Technical Abstract: A 6-year field study evaluated 52 sunflower, Helianthus annuus L., accessions, 20 breeding lines, and 9 interspecific crosses for resistance to infestation by naturally occurring populations of the red sunflower seed weevil, Smicronyx fulvus LeConte (Coleoptera: Curculionidae). Germplasm with potential sources of resistance to attack was identified. The accession PI 162453 averaged only 8% damaged seed per head in 3 years of testing and PI 431545 averaged 8% damaged seed per head in 4 years of trials. The accessions PI 431542 and PI 650375, which were tested for five years, averaged 5% and 10% damaged seed per head, respectively over the study. PI 431542 averaged less than 6% in all but one year of testing. Additional accessions that appeared promising in two consecutive years of trials included PI 195573, PI 219649, PI 250085, and PI 432516. Hybrid 894 consistently had high seed damage from S. fulvus feeding. Results revealed potential for developing resistant genotypes for decreasing seed feeding injury by the red sunflower seed weevil. Research is in progress to introgress resistance genes from the identified lines into cultivated sunflower through conventional breeding facilitated by the use of marker-assisted selection.