The 26-residue toxin from Staphylococcus aureus, delta-hemolysin, is thought to act by traversing the plasma membrane. The structure of this peptide, in methanol solution, has been investigated by using high-resolution NMR in combination with molecular dynamics calculations. The 1H NMR spectrum has been completely assigned, and it is shown that residues 2-20 form a relatively stable helix while the residues at the C-terminal end appear to be more flexible. The structures were calculated only from nuclear Overhauser effect data and standard bond lengths. It is shown that the results are consistent with 3JNH-alpha CH coupling constants and amide hydrogen exchange rates.