Paper attempts to empiricaly verify a non-linear (parabolic) dependence of employment in Poland on minimum wage to average wage ratio (Kaitz coefficient). The aim of the analysis is to find the optimal value of the Kaitz coefficient. The obtained result confirms the hypothesis on a non-linear nature of the investigated dependence. However, during the minimum wage evaluation process it is worth noting that the Kaitz coefficient's influence on the employment is bi-directional. Increase in the Kaitz coefficient value will only have a negative effect on employment after a certain threshold is crossed. Results pre-sented in the paper allow to identify such a critical value and to establish the coefficient value intervals with negative and positive influence on employment.