The essential oil of OCIMUM KILIMANDSCHARICUM Guerke, growing wild in Rwanda, was investigated by LSC, GLC and GC-MS. The oil contained 62% 1.8-cineole, indicating the occurrence of a new chemotype of the species concerned. In addition to 1.8-cineole, 16 oxygen-containing compounds and 14 monoterpene hydrocarbons were identified, of which limonene and beta-pinene were the main components. Most of the constituents were not previously known to be present in the essential oil of O. KILIMANDSCHARICUM.