Pension insurance is a social insurance program by which a member of the system, or in other terms his employer pays funds or contributions from the salary during his working life. In this way retired members acquire the right to a pension, partly realized on their contributions made thus far. In the Republic of Croatia, the retirement system consists of 3 pillars. The first pillar includes a generational solidarity system in which funds are paid to current retirees, while the remaining two pillars of the retirement system are based on capitalized savings, in exemple on the collection and fertilization of funds to be paid to a member when he/she fullfils the defined requirements for his/hers pension. Retirement funds are an integral part of the financial system in the Republic of Croatia. This master thesis explains and analyzes voluntary retirementfunds in more detail. Voluntary retirement funds can be of open or closed type. The analysis of the market of voluntary retirement costs is focused on the analysis of the structure of assets and yields of voluntary retirement funds and the costs of the voluntary retirement fund. The possibilities of improving voluntary retirement savings and the problems of insufficiently developed voluntary retirement savings in the Republic of Croatia are also analyzed. The main goal of this paper is to analyze and determine how government incentive measures affect investment in a voluntary retirement fund.