The agricultural sector, although representing a smaller percentage of GDP in economically developed countries, continues to play an essential role in sustainable economic development, food security and the well-being of rural areas. In this context, investments in agriculture should not be seen only as support for the primary sector, but as a national strategy for inclusive development and the reduction of regional inequalities. This paper aims to analyze the impact of the development of the agricultural sector in two main directions: (1) in increasing the number of active farms and (2) in increasing the productivity of agricultural products. To better understand the relationship between agricultural investments and these two key indicators, the paper includes a comparative analysis between four European countries with different development and agricultural policy characteristics: Kosovo, Slovenia, Croatia and Bulgaria. These countries were selected to compare different economic realities and to assess the impact of different support policies on agricultural development, especially in the context of European integration and support from the Common Agricultural Policy (CAP). Through the analysis of statistical data, institutional reports and relevant literature, the paper argues that there is a positive and significant relationship between the development of the agricultural sector and the increase in the number of farms, as well as a significant impact on improving productivity.