A rapid, simple, sensitive and selective spectrophotometric determination of trace nitrite is described.The method is based on a diazotization-coupling reaction between dapsone and N-( 1-naphthy1)ethylenediamine dihydrochloride (NEDA) in a hydrochloric acid medium. The molar absorptivity and Sandell's sensitivity were found to be 7 . 2~1 0~ 1 mol-' cm-'and 0.00063 pg ml-', respectively. The calibration graph is linear for 0.002-0.6 pg in-' of nitrite. The interference effects of various cations and anions were also studied and reported. This method has been found to be applicable to the determination of nitrite in various water samples.