The volatile constituents ofMentha longifoliaL. were isolated by hydrodistillation and simultaneous distillation-extraction method in the Likens-Nickerson apparatus and analyzed by GC and GC/MS. Seventy compounds were identified, 62 positively and 8 tentatively. The major constituents were piperitenone oxide (44.2% and 57.2%), 1,8-cineole (15.14% and 8.44%), myrcene (10.02% and 6.27%), limonene (4.28% and 3.45%), β-caryophyllene (1.72% and 3.34%) and germacrene D (1.51% and 4.11%).