A titrimetric method is described for rapid assay of hyoscine content of organs of locally cultivated Datura metel Linn. Raw materials required (approximately 1.5 gm) are much less than those required for conventional percolation processes. Using the procedure, the flowers have been shown to be richest in hyoscine, only minimal levels of alkaloids being detected in the fruits. Furthermore, the total alkaloid content of D. metel has been shown to peak in the hot dry season, and at its lowest during the rainy season in Ibadan.