The ESI funds are designed to support regional development by providing financial assistance to improve infrastructure, create jobs, and boost economic growth. Although they represent an essential source of investment for the member countries, at the end of the multiannual financial framework 2014-2020, the ESI funds absorption rate is 76%. Therefore, evaluating the ESI funds' efficiency is essential. Based on the bibliometric analysis, this research undertook a comprehensive examination of the literature review in his field. The bibliometric analysis generated 134 references from the Clarivate Analytics Web of Science Core Collection database. Research findings derived from this investigation establish that absorption capacity is the most relevant indicator for evaluating ESI funds' efficiency. The most commonly used method in research is Data envelopment analysis (DEA). The highest number of papers were published in Romania and Italy. Furthermore, the University of Murcia and Bucharest University of Economic Studies represent the most remarkable institutions.