Vapors collected from TNT, RDX and composition B explosives maintained at 25C and 70C were analyzed using a gas chromatographic/mass spectrometric technique to identify the most prominent vapor components. A gas chromatograph equipped with electron capture and flame ionization detectors also was used to screen vapors for components present at concentrations below the sensitivity of the GC/MS. Cyclohexanone which could have significance in development of an explosive or mine detector was identified in vapors from RDX and composition B. Water vapor, carbon dioxide, probably nitrous oxide and a number of unidentified compounds were evolved from all samples. It may be possible to identify these unknown compounds present at trace levels, but extreme analytical care and precaution to avoid contamination would be required. In this regard, differentiation between compounds which are incorporated into the explosive matrix during manufacturing and those which are adsorbed from air by the explosive at a later time is also required.