The ion pair (IP) of levamisole with BiI4 - (SbI4 - ) for the levamisole-selective sensor with a PVC membrane containing - ions were developed. Thermal behavior of obtained IP was investigated by differential thermal analysis that would show the thermal stability and the character of the decomposition of the complex. The thermolysis of Lev+BiI4 - IP undergoes three stages that fit a theoretical interpretation. The linearity ranges of levamisole sensors function are 7.9 ×10-6 – 1×10-1 (7.9 ×10-5 – 1×10-1 ) M. The Nernstian slope of 50.6 – 53.4 mV pC−1 and detection limit of 5.0 × 10−5 – 1.5 × 10−4) M. The working range of pH is 2.8 – 6.0. The efficiency of the use of electrodes for levamisole content control in pharmaceutical preparations was shown by direct potentiometry and potentiometric titration methods.