Reversed-phase HPLC was used for the determination of paclitaxel and related compounds in both isocratic and gradient mode, using four different HPLC columns. With the selected acetonitrile–0.05 M ammonium acetate gradient, 13 taxanes of a standard mixture were clearly separated on a phenyl column within 30 min. The system was tested with plant extracts and unknown taxanes were identified by LC–MS with an electrospray interface. A specialty 'taxane' column also achieved a baseline resolution of the 13 taxanes, but in 55 min. The developed methods were applied to the analysis of plant extracts.