Artesunate (ART) is a readily available anti malarial in combination therapy. The assay method has posed a challenge because it does not have a readily recognisable absorption chromophore needed for UV spectroscopy. A simple and rapid assay method involving two reaction steps has been developed for assay of ART in pharmaceutical formulations. The method involves basic reaction of ethanolic solution of ART with 0.1N sodium hydroxide and then neutralisation and acidification of this reaction mixture with 0.1M solution of acetic acid in 20% ethanol. This gave a good UV spectrum for ART with λmax at 242nm. HPLC analysis of this mixture revealed the presence of two prominent peaks. The peaks were further identified with HPLC-mass spectrometer to possibly be those of glycal and furanose acetal. The method was validated for stability, linearity, accuracy, intra- and inter-day precision and was used to assay ART in commercial tablets. The method is simple and suitable for the assay of ART in pharmaceutical formulations.