The purpose of the paper was to identify the economic efficiency of edible potato cultivation on the basis of the Gross Margin. Data concerning cultivation of the Owacja cultivar of potato came from a farm located in the Biała Podlaska Commune in the Lubelskie Voivodship. Potatoes were grown in 2015-2016 on a production plantation with the surface area of 1.6 ha, on a good rye complex soil. The evaluation of economic potato production included direct costs, value of harvested crop and gross margin. It was observed that potato production in 2015-2016 was profitable. The value of production of the Owacja cultivar of edible potato amounted to PLN 16,370.00/ha on average, while the value of gross margin PLN 5,851.50/ha. The greatest share in the structure of incurred costs was held by specific costs (42.02%), seed-potatoes (34.46%), natural fertilization (manure) (11.88%), followed by costs of plant pesticides (6.09%), as well as mineral fertilizers (5.55%).