We developed an enzyme-linked immunosorbent assay-based assay to assess Haemophilus ducryi binding to extracellular matrix (ECM) proteins. H. ducreyi 35000HP bound to fibronectin, laminin, and type I and III collagen but not to type TV, V, or VI collagen or elastin. Isogenic strains with mutations in ftpA or losB bound as well as the parent, suggesting that neither pill nor full-length lipooligosaccharide is required for H. ducreyi to bind to ECM proteins.