A cloud point extraction procedure for the preconcentration of copper, nickel, iron and zinc ions in various samples has been described. Analyte ions in aqueous phase are complexed with 3-((indolin-3-yl)(phenyl)methyl)indoline (IYPMI) and following centrifugation quantitatively extracted to the aqueous phase rich in Triton X-114. The surfactant-rich phase was dissolved in 2.0 mol L(-1) HNO(3) in methanol prior to metal content determination by flame atomic absorption spectrometry (FAAS). The effects of some parameters including, the concentrations of IYPMI, Triton X-114 and HNO(3), bath temperature, centrifuge rate and time were investigated on the recoveries of analyte ions. At optimum conditions, the detection limits of (3 SDb m(-1)) of 1.6, 2.8, 2.1 and 1.1 ng mL(-1) for Cu(2+), Fe(3+), Ni(2+) and Zn(2+) along with preconcentration factors of 30 and enrichment factor of 48, 39, 34 and 52 for Cu(2+), Ni(2+), Fe(3+) and Zn(2+) respectively, were obtained. The proposed cloud point extraction has been successfully applied for the determination of metal ions in real samples with complicated matrix such as biological, soil and blood samples with high efficiency.