Fairness of taxation is one of the inevitable topics in the domain of evaluating the effects of taxation within the national framework. The path towards instituting fair taxation is burdened by many obstacles, which are particularly prominent in times of complex and changing socio-political and economic trends. Given that each period has its own traps, the full content, true meaning and factual acceptance of fair taxation postulates have to be constantly reexamined. In that context, this paper examines fairness of taxation and its reflections in the sphere of contemporary taxation. Considering that fair taxation is a reliable support for building correct tax-law relations, the author provides a detailed analysis of fundamental requirements for its implementation, expressed in the form of general tax obligation (tax universality) and equal distribution of tax load. In particular, the author clarifies the occurrence of a relatively limited effect of the general tax obligation in contemporary conditions, caused by the existence of tax exemption and tax reliefs, and elaborates on the dimensions of horizontal and vertical equity in taxation. The paper also provides an in-depth examination of tax system transformations, achieved as a result of conducted tax reforms in the past few decades, with the aim of confirming the hypothesis about the dwindling significance of the ability-to-pay principle (paying taxes according to economic capacity) as a fundamental rule for modelling contemporary tax structures.