Spectrophotometric procedure for the determination of metal ion representatives from the three subgroups of lanthanide series, namely Neodymium (III) & Samarium (III) of Cerium group; Gadolinium (III) & Terbium (III) of Terbium family and Dysprosium (III) & Holmium (III) of Yttrium family has been studied using 1-(2-pyridylazo)-2-naphthol (PAN) as a chromogenic reagent in micellar media. The reported procedure avoids the use of carcinogenic molecular solvents. The method is based on the formation of an intense red colored ML3 type of complex (L=PAN and M= Ln (3+)) in the pH range 8.5-9.5, soluble in all the three micellar media under study, viz. Sodium dodecyl sulphate (SDS), Cetyl trimethyl ammonium bromide (CTAB) and Triton X-100. All the systems show (6.2 - 9.18) x 10(4), (4.4 - 8.5) x 10(4) and (4.3 - 7.8) x 10(4) mol(-1) cm(-1) dm(3) molar absorptivity and (1.5 - 3.02) x 10(-4), (1.7 - 2.96) x 10(-4), (2.1 - 2.8) x 10(-4) mu g cm(-2) Sandell's sensitivity for Triton X, CTAB and SDS respectively. The tolerance limits towards several foreign ions are also reported.