Highly sensitive and selective direct spectrophotometric method is proposed for the determination of molybdenum in various real samples. 2-hydroxy-1-naphthaldehyde-p-hydroxybenzoic hydrazone reacts with Mo(VI) forming an orange red coloured soluble complex in aqueous dimethyl formamide which has a λmax at 450 nm in the pH range 2-3. The system obeyed Beer's law in the range 0.959-9.59 µ g/ml of Mo (VI). The molar absorptivity is 0.65 ± 0.002×10P 4 P 1 molP-1 P cmP-1 P and the Sandell's

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... ty is 0.0147 µg/cmP 2 P. The standard deviation of the method for ten determinations of 9.59 µ g/ml of Mo (VI) is 0.008. The correlation coefficient (γ) of the calibration equation for the experimental data is 0.9995. Studies on effect of diverse ions showed almost all the anions, except Tartrate, Fluoride and Ascorbate and a majority of the cations do not interfere. The interference from Fe(III), Ti(IV), Zr(IV), Th(IV) and Cu(II) was eliminated using suitable masking agents. The direct method was applied for the determination of molybdenum in steel and alloy samples.