Simple and sensitive spectrophotometric and spectrofluorimetric methods are described for analysis of acyclovir and acebutolol hydrochloride. The proposed methods are based on oxidation of the selected drugs with cerium(IV) ion in acidic medium with subsequent measurement of either the decrease in absorbance at 320nm or the fluorescence intensity of the produced cerous(III) ion at 361-363nm (excitation at 250nm). Beer's law obeyed from 2 to 8, 0.25 to 2.5microgcm-1 acyclovir, 1 to 7 and 0.25 to 2.5microgml-1 acebutolol hydrochloride, using the spectrophotometric and spectrofluorimetric method, respectively. The proposed method were successfully applied for determination of the selected drugs in their pharmaceutical preparations with good recoveries.