Twenty-six tropane alkaloids were identified from the root-bark of Erythroxylum monogynum by GC and GC-MS and twenty of these alkaloids had not previously been reported as constituents of the root-bark. 3 alpha-(3',4',5'-Trimethoxybenzoyloxy)tropane was the main base and in addition, three new alkaloids were identified as 3 alpha-isobutyryloxynortropane, 3 alpha-(4-methylvaleroyloxy)tropane and tentatively, 3 beta-phenylacetoxytropane.