The category of fattening bulls significantly contributes to the total beef production in the Czech Republic which amounted to 72 ths. tons in 2016. A reasonable level of profitability is necessary for further increase of beef production. The analysis of data provided by fattening bull operations for the period from 2013 to 2016 was performed. The average total costs including the purchase price of a weaned animal were 32 ths. CZK per fattened bull. The average selling price was 32 ths. CZK per bull and thus, the fattening operations suffered a loss (negative profitability on average -7 %) even when the support payments were included in the calculation. It was confirmed that lower costs per animal were found in larger – size operations with more fattened animals. Daily weight gains, prices of purchased weaned animals, and selling prices of bulls were identified as the parameters with the highest economic impact.