TGF-beta 1 plays a critical role in inflammatory and repair processes due in part to its ability to provide a potent chemotactic stimulus for inflammatory cells such as neutrophils and monocytes and for fibroblasts which initiate the fibrogenic response. In the present study, we have used synthetic oligopeptides representing the amino acid sequence of the 12.1 kDa monomer of human TGF-beta 1 in an effort to identify a chemotactic epitope on the molecule. A seven residue peptide containing residues 368-374, Val Tyr Tyr Val Gly Arg Lys, was demonstrated to be capable of inducing chemotactic migration of human peripheral blood neutrophils, monocytes, monocyte leukemia cell line THP-1, and infant foreskin fibroblasts. Furthermore, larger peptides from the carboxy-terminal portion of TGF-beta 1 that contained residues 368-374 also induced migration of these cell types. None of the peptides representing the complete amino acid of TGF-beta 1 monomer were able to compete with [125I]hrTGF-beta 1 for binding to TGF-beta cell surface receptors or fibroblasts or THP-1 cells. Implications of these observations are discussed.