Anthocyanin composition of black raspberry (Rubus occidentalis) was studied using high-performance liquid chromatography coupled to photodiode array (PDA) detection and electrospray ionization mass spectrometry (LC-ESI/MS) and tandem mass spectrometry (MS/MS). Pelargonidin 3-rutinoside was isolated and identified in black raspberries using HPLC, UV-Vis spectroscopy, MS, and NMR spectroscopy. No pelargonidin derivative had been previously found in Rubus occidentalis. In addition, the presence and identities of four previously reported anthocyanins (cyanidin 3-glucoside, cyanidin 3-sambubioside, cyanidin 3-rutinoside and cyanidin 3-xylosylrutinoside) were confirmed by HPLC/MS and MS/MS analyses. © 2005 Elsevier Ltd. All rights reserved.