Three major compounds, 2-acetyl-1-pyrroline (APY), 2-acetyltetrahydropyridine (ATHP) and 2-ethyltetrahydro-pyridine (ETHP), have been identified as responsible for the mousy off-flavor in wines, although to date quan-tification data reported in the literature are limited. A simple method for simultaneous quantitation, by SBSE-GC-MS, of these N-heterocyclic compounds was developed. Both previously reported tautomers of ATHP, 2-acetyl-1,4,5,6-tetrahydropyridine and 2-acetyl-3,4,5,6-tetrahydropyridine were identified. The limits of detec-tion and quantification of the method were determined in white, rose ' and red wines and are lower than pre-viously published concentrations in spoiled wine. ETHP was detected in almost all wines produced with limited use of SO2. ATHP was detected in almost all wines suspected of mousiness whereas APY was only detected in few cases. This method will provide a support for further studies aimed at understanding the phenomena that in-fluence the occurrence of mousy off-flavor and the oenological parameters that modulate its expression.