Abstract A new titrimetric method for the determination of l-ascorbic acid with standard cupric salt solution, e.g., cupric sulfate or cupric acetate, is described. The mechanism of the reaction is discussed. The method is simple, rapid, and sensitive to determine amounts as low as 25 μg of l-ascorbic acid. The experimental error for pure l-ascorbic acid does not exceed ± 2%. Analysis of l-ascorbic acid, certain pharmaceuticals, and foodstuffs by the proposed method and the N-bromosuccinimide method for similar results is reported.