A multi-component analysis with partial least square (PLS) method using flow injection-diode array detector-absorptionspectrophotometry is studied in this paper. The method has been applied to the simultaneous determination of Zn, Cd and Pb. The spectrophotometric determination is based on the reaction of the metallic ions and meso-tetra (4-trimethylammonium phenyl) porphyrin (TAPP) forming colored complexes. The overlapped spectra of these complexes are collected by charge coupled device (CCD)-diode array detector and the multi-wavelength absorbance data are processed using PLS algorithm. The variables of chromogenic reaction and flowinjection were optimized and the proposed method is validated on determination of Zn, Cd and Pb in a water standard reference material and the samples of beverage, powdered corn and powder milk. The determination results of samples are in good agreement between the proposed method and AAS. The average spiked recoveries are 89.6-103.2% with R.S.D. of 2.8-7.1%. The sampling rate is 30 samples h−1.