A simple gas chromatographic technique was developed for the quantitative determination of organic acids and reducing sugars in fermenting cucumber juice. Acids and sugars were simultaneously chromatographed as their trimethylsilyl derivatives with no prior fractionation reqdired. A 3% OV-17 column provided resolution of acids, sugars and trimethylsilylimidazole, the silylating agent and solvent. Accurate quantitation of fructose and glucose consumption and lactic acid production were qbtained for cucumber juice samples fermented by Lactobacihs plantarum culture. The average and range of the average deviations of duplicates for all samples tested were ±0.015% and 0.001–0.045%, respectively. A study on the recovery of added acetic acid, lactic acid, glucose, and fructose was conducted with an average % redovery of 98.4% and a range of 95.2–101.1%.