A spectrophotometric and first derivative spectrophotometric determination of Ni(II) is carried out with  1-nitro-2-napthol as complexing reagent in aqueous phase using non-ionic surfactant Tween 40. The nickel is determined in the range 1.7-120 ngmL-1 with detection limit (2s) of 1.7 ngmL-1. The molar adsorptivity and Sandell’s sensitivity are emax 1.0 x (104 mol-1 cm-1) and 5.8 ngcm-2 at 452 nm. The optimum pH of the complex is 8. the critical micelle concentration (cmc) of Tween 40 is 5%. Adsorption studies in the first derivatives mode is carried out to determine the adsorption maximum of the complex fro higher sensitivity and to overcome interference due to the presence of certain other metals ions. The presents method is compared with that of AAS and no-significant difference is noted between the two methods at 95% confidence level.  The methods has been applied for the determination of Ni (II) in industrial waste water and edible oil samples.