Fourteen commercial samples of the popular Brazilian aphrodisiac Catuaba specified as bark drugs of Anemopaegma, Erythroxylum and Trichilia species were examined for identity and purity. Only a minority of the examined Catuaba samples contained the crude drugs claimed on the labels. More than half of the products were adulterated with different crude drugs. The majority of the samples contained a bark originating from Trichilia catigua. The TLC fingerprints confirmed the heterogeneity, in 50% of the samples tropane alkaloids of various concentrations were detected. TLC and HPLC methods for separation and identification of the tropane alkaloids were developed and their analytical data (RF values, retention times, ESI-MS) given. The structure elucidation of the two main alkaloids, catuabine D and its hydroxymethyl derivative, is presented. The 1H- and 13C-NMR assignments of these alkaloids are discussed with regard to literature data. Neither aqueous nor methanolic extracts of the Trichilia catigua reference material nor alkaloid-enriched fractions of commercial samples showed any effect on the rabbit corpus cavernosum in an in vitro test.