The thesis upon which this paper is based is existence of a spatial data infrastructure in a specific form, at a specific moment and at a specific level, which is directly linked to the level of technological and social development. Establishing a spatial data infrastructure actually means improving the existing infrastructureand can be defined as a number of activities aiming at easier access to and dissemination of the existing spatial data, and easier and more efficient use of them. This paper considers improvement of the spatial data infrastructure in Croatia as a public project ofpermanent character and of special social interest. Taking into consideration a four-year improvement period, a cost-benefit analysis was made, the financial indicators of which show that the best efficiency is accomplished if the project initial time period is shorter.