EN
In this paper a thesis was put forward, that the prevalence of fiscal unsustainability in modern economies can be described as the government failure. Therefore, the purpose of this article is to present the lack of fi scal sustainability in the light of the concept of government failure, and fi scal sustainability as a requirement to improve the quality of public governance. In the fi rst part of the article the traditional approach to market failure and the resulting need for public regulation was presented, pointing out its defi ciencies. Part two is dedicated to description of the essence of fi scal unsustainability as a symptom of government failure in the allocation, redistribution and economy stability. The fi nal section focuses on the issues of ensuring fi scal sustainability as a requirement to improve the quality of public governance, contributing to the reduction of state failure.