A derivative UV spectrophotometric method for the determination of ambroxol in tablets was developed. Determination of ambroxol in tablets was conducted by using first-order derivative UV spectrophotometric method at 255 nm (n = 5). Standards for the calibration graph ranging from 5.0 to 35.0 mug/ml ere prepared from stock solution. The proposed method was accurate with 98.6 +/- 0.4%, recovery value and precise with coefficient of variation (CV) of 1.22. These results were compared with those obtained by reference methods, zero-order UV spectrophotometric method and reversed-phase high-performance liquid chromatography (HPLC) method. A reversed-phase C-18 column with aqueous phosphate (0.01 M)-acetonitrile-glacial acetic acid (59:40:1, v/v/v) (pH 3.12) mobile phase was used and UV detector was set to 252 nm. Calibration solutions used in HPLC were ranging from 5.0 to 20.0 mug/ml. Results obtained by derivative UV spectrophotometric method was comparable to those obtained by reference methods, zero-order UV spectrophotometric method and HPLC, as far as ANOVA test, F-calculated = 0.762 and F-theoretical = 3.89, was concerned, (C) 2003 Elsevier Science B.V. All rights reserved.