A simultaneous second order derivative spectrophotometric method was developed for the determination of chromium (VI) and vanadium (IV) using 2-hydroxy-3-methoxy benzaldehyde thiosemicarbazone (HMBATSC) as a chromophoric reagent. The reagent reacts with chromium (VI) and vanadium (IV) at pH 6.0. Cr (VI) and V (IV) present in the mixture were simultaneously determined without solving the simultaneous equations by measuring the second order derivative amplitudes at 410 nm and 440 nm respectively. The derivative amplitudes obey Beer’s law in the range 0.143-3.44 μgml-1 of Cr (VI) and 0.102-4.068 μgml-1 of V (IV). Large number of foreign ions does not interfere in the present method. The present simultaneous method was used for the determination of micro amounts of chromium (VI) and vanadium (IV) in synthetic mixtures.