E-government diffusion is phenomenon of last years in all countries around the world. This term includes both the development and adoption of e-government by citizens and is part of a smart solution for their interaction. This paper attempts to provide an analysis of the level of the e-government diffusion in two post-communist countries, Czechia and Kazakhstan, over the last decade. The objective of this study was, within the above-mentioned diffusion, to ascertain the development of e-government and citizen e-participation in both economics between the years 2010 and 2020. For this purpose, the E-Government Development Index and the E-Participation Index were adopted. The established assumption of a better position of the Czechia as a high-income country was verified. However, the results show a better position of Kazakhstan in both components of the e-government diffusion.