The conditions for thin-layer chromatographic determination of curcumine in turmeric root powder and spice-mixtures have been optimized. Separation of the methanolic extract on silica gel thin-layer plates with chloroform-acetic acid (80∶20) gave the best results. The curcumine can be directly determined on the layer by fluorometric scanning, after conversion to rubrocurcumine with a mixture of boric acid and oxalic acid as spray reagent. Determination of the amount of turmeric root powder in spice mixtures by determining the curcumine content is only possible if the curcumine content of the turmeric root powder used is known because different turmeric root powders may have different curcumine contents.