The combination of potentiometric methods with multivariate calibration techniques allows complex mixtures to be analyzed. In this study, a new method was developed and reported for simultaneous determination of copper(II) and zinc(II) cations in a mixture by titrimetric methods. The developed method permits simultaneous cation analysis with low detection limits, just by using a pH electrode. This work has achieved the challenging goal of developing a cost-effective and applicable method that can be applied in most laboratories due to independence of any chemical instruments. Partial least squares 1, one of the multivariate calibration techniques, was used in the analysis of titrimetric data. Copper(II) and zinc(II) were simultaneously determined with approximately 5 ppm detection limits and the developed method was validated by performing the titration with known sample mixtures and a certificated alloy sample.