Nowadays, it is almost impossible to imagine a system of social security without pension system. Pension insurance is certainly one of the most important factors of social security, which contributes to strenghtening social cohesion, solidarity in society and which elevates the standard of citizens as they transit from the working stage of life to the retirement. Furthermore, it is the bases of security and stable functioning of every modern prosperous state. Some of the basic functions of retirement insurance are: income redistribution throughout the life span, individual and national savings and maintaining social cohesion by alleviating poverty during old age and inactivity. The pension system operates according to a very simple principle. During the working period, pension scheme members and their employers make pension contributions with the aim of enjoying the 'savings' after the retirement. Retirees are entitled to a pension in the amount as a result of multiplication of length of service and points value. In addition to the legal framework, economic, social and demographic trends stipulate and shape the pension system and guide its movement. By the valid regulations, three pension pillars have been established in the Republic of Croatia: mandatory pension insurance based on intergenerational solidarity in the first pillar and mandatory second pillar wich is based on obliagoty saveings and voluntary pension insurance based on individual capitalized savings. In the last few years, voluntary retirement savings have proven to be a useful additional source of income after retirement. The focus of this paper is on the increasingly attractive form of financing through voluntary pension funds, with an focus on closed pension funds. An analysis will be conducted with regard to organizational, structural and technical assumptions of this form of savings, while simultaneously observing the role and treatment of the main actors of the voluntary retirement saveings Finally, the specific voluntary pension fund of the HEP Group will be analyzed in order to give a value assessment and recommendations for this form of financing / savings.