The study presents a dynamic deterministic factor analysis of labour productivity in the Kozloduy Nuclear Power Plant (NPP) for the period 2017 ÷ 2022. The aim of that study is to reveal the quantitative influences of the factors of gross electricity and heat produced or of operating revenues over the number of employed persons on the development of the labour productivity indicator, expressed by the production volume or by the production value in the Kozloduy NPP for the period 2017 ÷ 2022 through the averaged chain substitution method. The study outlines the quantitative influences of gross electricity and heat produced, the operating revenues, and the number of employed persons on the quantitative deviation of the labour productivity indicator in the Kozloduy NPP for the period 2017 ÷ 2022. The results of the deterministic factor analysis make it possible to draw reasonable conclusions and to reveal the trends in the development of the factors of gross electricity and heat produced, operating revenues, and the number of employed persons, as well as the resultative indicator of labour productivity in the Kozloduy NPP for the period 2017 ÷ 2022.