The aim of the study was to present cost calculations and to examine the profitability of starch potato production in a family farm in the county of Łuków, cooperating with PPS PEPEES in Łomża in 2016-2017. The highest yield of starch potato tubers was obtained in 2017, and the value of production from 1 ha in particular years ranged from 8,517.75 PLN/ha in 2016 to 10,123.0 in 2017. The high volatility of income in individual years was dictated by the amount of the yield and the different price obtained per unit of production. The cost-effectiveness of growing starch potato was determined by direct costs. The largest costs in the structure of direct costs were related to the purchase of seed potatoes and costs of fuel and transport of potatoes to PPS PEPEES. The highest profitability of starch potato was obtained in 2017.