The article deals with the problem of social insurance of farmers as an instrument used by the state to exert an influence on the economic situation of farms. Since premiums and benefits are particularly important factors of this influence an analysis has been conducted of these two elements of the farmers' social insurance system. The results of the conducted analysis show that insurance premiums are a burden of a character resembling taxes and that the greater part of this burden is borne by small farms. On the other hand, the group of small farms also has the highest share in the benefits stemming from the insurance system. Since small farms are only weakly linked to the market it can be stated that welfare function is the most important function of the farmers' social insurance system.