Notable efforts are on-going to improve Irish potato production in Plateau State, the major producer of the crop in Nigeria. However, little attention has been given to the profitability of the enterprise while the determinants of profitability level are scanty in the literature. Thus, paper analyses the profitability of Irish-potato farming using primary data from 252 Irish potato farmers in Plateau State, Nigeria. Cost structure and profitability level of Irish potato farming were investigated using farm budgeting technique while probit regression model was used to examine the determinants of profitability level of Irish potato farms. Irish potato farming was found to be profitable with most (53.97%) farmers at high profitability level. The net farm income was ₦604, 245.81 per hectare with returns per naira spent of ₦1.70. The cost structure showed that costs of seeds, labour and fertilizer made up the largest share of the total cost of production per hectare. The probability that a farm will be at high profitability level was determined by agrochemicals, sex, farm size and labour at 1% level, respectively. It was concluded that increasing agrochemicals, reducing farm size and labour and being a male farmer will improve profitability level of Irish potato farms. This study recommended that increased use of agrochemicals and more efficient use of labour and farm land be encouraged among potato farmers increase their profitability level.