In order to get fuller information on the influence of hydroxyl groups on alkali colour reactions a number of flavonols of types uncommon in Nature have been prepared and examined. Though the correlation between structure and alkali colour reactions is complex, when applied with care the reactions can be used for diagnostic purposes. The alkali colour reactions of the flavonols with 2′∶3′ and 2′∶3′∶4′ disposition of hydroxyl groups are not prominent and their fluorescence properties are also very feeble.