The volatile compounds extracted from both traditional and industrial chorizo-a dry fermented sausage-were analysed by gas chromatography/mass spectrometry (GC/MS). One hundred and twenty-six peaks were detected relating to volatile extracts of which 115 were identified. The substances identified belonged to several classes of chemical: acids, alkanes, alcohols, aldehydes, sulphur compounds, ketones, esters, ethers, phenolic compounds, aromatic hydrocarbons, lactones, nitrogen compounds, terpenes, chloroform and benzofurane. Among the major compounds isolated were acetic acid, allyl-1-thiol and phenol. Larger quantities of most of the chemical groups were found in industrial compared to traditional chorizo, except for sulphur compounds. Typical breakdown products derived from lipid autooxidation were virtually negligible in chorizo. Of the chemicals isolated, sulphur compounds, phenols, acids, ethyl esters and carbonyls could have particular importance to the overall chorizo flavour. In addition, the changes in the proportions of volatile compounds during the ripening of chorizo were tracked. Most of the volatiles increased during ripening, especially acids, alcohols, esters, phenols, ketones and terpenes. On comparing the distribution of the sulphur compounds observed in chorizo with that of garlic, some noteworthy differences were observed. The reason for these differences is based upon several transformations of the sulphur compounds derived from garlic during the ripening and storage of chorizo.