Diversification of the agricultural production potential often implies the differentiation of the achieved farming productivity due to its effect on the agricultural resources and structural processes. The article aims to examine the diversity of the production potential in the agricultural sectors of the EU candidate countries (CC) and the Eastern Partnership countries (EPC) and its impact on the variety of the achieved productivity, as well as to present changes in the analyzed indicators in the years 2006–2017. A synthetic measure of agricultural development and a linear regression analysis were applied in the article. The research revealed that Belarus may be distinguished with regard to its production potential, as well as the achieved productivity. In most countries (with the exception of Montenegro and Macedonia), an increase in the value of the synthetic measure of the possessed potential has been recorded in the studied period. However, the synthetic measure of the agricultural productivity level displayed an insignificant raise only in half of the countries surveyed.