The aim of the research was the acquisition of information concerning the operation of the agricultural price system under transition, the degree of adjustment of prices to equilibrium levels, and the responsiveness of agricultural supply and of food demand systems to changes in agricultural prices. This objective is of value for reasons of theory and policy. The research was conducted in three countries -Bulgaria, Romania and Slovenia -which exhibit significant differences in their levels of development, the nature of their institutions and the economic conditions prevailing at the beginning of the transition, and in the reform policies followed. The results indicate that in Bulgaria and Romania, long delays in introducing institutional reforms brought about the retention of non-competitive elements in the market structure which did not allow the agricultural markets and the agricultural price system to function properly. In Slovenia, price responsiveness of agricultural supply is substantial and price adjustment to equilibrium levels significant, while price response of agricultural supply in Bulgaria is very low with factors other than prices having a stronger impact on production.