Six tropane alkaloids were isolated from the Sri Lankan endemic plant Erythroxylum zeylanicum O.E. Schulz (Erythroxylaceae) and structurally elucidated by NMR and MS measurements. Three of them, erythrozeylanines A [1R,3R,5S,6R-6-acetoxy-3-(3',4',5'-trimethoxybenzoyloxy)tropane], B [cis-3 beta-(cinnamoyloxy)tropane], and C [cis-6 beta-acetoxy-3 alpha-(cinnamoyloxy)tropane] are new, whereas the others have already been found in other Erythroxylum species. For the first time, the absolute configuration of a tropane alkaloid (erythrozeylanine A) has been determined by quantum chemical CD calculations.