[reaction: see text] Nitrated fatty acids act as endogenous peroxisome proliferator-activated receptor gamma (PPARgamma) ligands and nitric oxide (NO) donors. We describe the first specific preparation of the two regioisomers of nitrooleic acid, (E)-9-nitrooctadec-9-enoic acid (1) and (E)-10-nitrooctadec-9-enoic acid (2), from cis-cyclooctene and monomethyl azelate, respectively. These syntheses rely upon a Henry condensation between a nine-carbon nitro component and a nine-carbon aldehyde. Preliminary chemiluminescence NO detection studies reveal the ability of these nitrated fatty acids to release NO.