Abstract: Novel reagents and the rapid technique were developed for the simultaneous determination of water and ene-diols or thiols in chemical products, drugs and other materials which are inaccessible for direct K. Fischer titration. The reagents include iodine, tetramethylammonium iodide or potassium iodide, non-toxic organic or inorganic base adapted to provide a pH in range of 5.5 to approximately 8.0 (diethanolamine, thriethanolamine, sodium acetate or/and urea) in methanol or another alcohol mixed with N,N-dimethyl-formamide, or with formamide, or with dimethyl sulfoxide and N,N dimethylformamide mixture as a solvent. The use of the reagents is based on the consecutive titration first a) of an ene-diol or thiol by the novel reagents and then b) of water by a conventional K. Fischer reagent in the same cell in a system protected from water vapour and oxygen, with the help of the double burette for electrometric location of the end point in both titrations (or a multistage titroprocessor).