For several years we have been conducting an analytical investigation on the aroma of roasted and ground coffee in order to extend our knowledge of the aroma constituents. One hundred and fifty-eight compounds were isolated from the solvent extract of steam condensate of roasted and ground coffee by gas-liquid chromatography and identified by spectral means. Thirty of these compounds have not been reported in roasted coffee. They were identified by comparison of the unknowns with authentic samples—i.e., infrared spectra, retention times on two GLC columns and, in a number of cases, mass spectra. Adding the new compounds resulting from the present investigation to those mentioned in a review summarizing constituents known up to April 1967, it can be concluded that at least 318 volatile constituents occur in roasted coffee. In spite of the large number of volatile components identified, the aroma reconstitution to form a complete coffee aroma remains to be solved. It is apparent that no single aroma component has been found responsible for the coffee aroma; that problems of aroma component stability must be solved; and that probably important aroma components still await detection.