A simple, rapid, highly sensitive and new simultaneous spectro- photometric method is proposed for the analysis of chromium(VI) and vanadium(V) without separation by using 3,4-dihydroxybeznaldehyde isonicotinoyl hydrazone (3,4-DHBINH). The reagent reacts with the two metal ions in acetic acid-sodium acetate buffer of pH 5.5 and gives maximum absorbances at 400 nm and 360 nm for chromium(VI) and vanadium(V), respectively. Both the metal ions gives 1: 1 (M:L) complexes with the reagent. Effect of various diverse ions also studied. The instability constants for the two complexes were also evaluated. This method was successfully applied for the determination of chromium(VI) and vanadium(V) in various spiked samples. The validity of the method was checked by comparing with the results obtained by atomic absorption spectrophotometry.