The article was focused on determining the economic efficiency and arguing the economic calculations connected with the economic efficiency of the fish breeding within the agricultural farms of the Republic of Moldova. In order to make an analysis, the author proposed the idea of creating a model farm breeding fish in a basin of water with a linear area of 10 hectare, the one that can be implemented and managed within a family farm. The economic calculations connected with fish breeding have been done taking into consideration the following aspects: assessment of the necessary investments, planning the annual revenues from sales, calculation of the annual consumptions and calculation of the final economic results. As a result of practicing the entrepreneurship activity within this farm designed for fish breeding, we determined that it is possible to obtain an annual sufficient profit for the further development of the mentioned business.