Mentha piperita leaf essential oil was obtained by hydrodistillation method. It yielded about 2.4% (v/w). The Physicochemical properties of M. piperita leaf oil were determined. The chemical composition of the essential oil of M. piperita was investigated using GC-MS technique. The gas chromatogram revealed detection of seventeen compounds. Monoterpenes, represented about 83% of the oil, of which 79.87% were oxygenated. Among the oxygenated monoterpenes, the most abundant components found was menthone (57.7%) followed by menthofuran (7.2%), 1,8- cineole (5.5%), isomenthone (3.8%), menthyl acetate (2.3%), pulegone (1.7%) and isomenthol (1.5%), whereas the most abundant hydrocarbon monoterpene is limonene (1.6%). This study confirmed that M. piperita grown under Sudan climatic conditions is menthone chemotype (M. piperita ct. menthone).