Purpose The goal of this paper is to describe the life cycle inventory (LCI) approach to steel produced by ArcelorMittal's Basic Oxygen Furnace (AMBOF) in Kraków, Poland. The present LCI is representative for the reference year 2005 by application of PN-EN ISO 14040:2009 (PN-EN ISO 2009). The system boundaries were labeled as gate-togate (covering a full chain process of steel production). The background input and output data from the basic oxygen furnace (BOF) steelmaking process has been inventoried as follows: pig iron, scrap, slag forming materials (CaO), ferroalloys, Al, carbon and graphite carburizer (material for carburization of steel), isolating powder, consumption of energy and fuels including natural gas, blast furnace gas and coke oven gas, electric energy, steam, air, oxygen, industrial water and heat, emission of air pollutants, waste, internal transport and land use. Main feature LCI steelmaking process was developed mainly on the basis of the following sources: site-specific measured or calculated data, study carried out by the AGH University of Science and Technology in Kraków, AMP Environmental Impact Report, study carried out by the Faculty of Mining Surveying and Environmental Engineering of the AGH University of Science and Technology in Kraków, literature information and expert consultations. The functional unit (FU) is represented by 1,677,987 Mg of steel, produced by BOF steelmaking process. Time coverage is 2005. Operating parameters as well as air emissions associated with the BOF steelmaking process were presented. The production data (steel) was given. The emissions of SO 2 , NO 2 , CO, CH 4 , CO 2 , dust, heavy metals (Cr, Cd, Cu, Pb, Ni and Mn) and waste (slag and gas cleaning sludge) are the most important outcomes of the steel process. Results With regard to 1,677,987 Mg of steel produced by AMBOF, the consumption of natural gas, blast furnace gas and coke oven gas amounted to 10,671,997, 755,094 and 13,222,537.6 m 3 /year, respectively. Electric energy, steam, air, oxygen and heat input amounts were in the order of 45,003,611.3 kWh, 21,646.03 Mg, 107,592,526 m 3 , 90,611,298 m 3 and 16,779.87 GJ, respectively. Direct emissions in air of SO 2 , NO 2 , dust, Cr, Cd, Cu, Pb, Ni, Mn, CO and CH 4 from three converters (Nos. 1-3) were on the order of 28.966, 71.331, 752.05, 0.025, 0.024, 0.0216, 0.0156, 0.0163, 1.5694, 540.449 and 0.364 Mg, respectively. Total CO 2 emission was 138,374 Mg. The amounts of slag and gas cleaning sludge were 276,709.64 and 16,749 Mg, respectively. Conclusions The LCI study resulted in the development of a database with a vast inventory of data regarding steelmaking process in AMBOF referring to the year 2005. The output of the AMBOF LCI study is a set of gate-to-gate LCI data for steel production in BOF technology. This is the first tentative study to express steel production in Poland in terms of LCA/LCI in the steelmaking industry. The FU chosen for the present study is 1,677,987 Mg of steel produced in a classical BOF. The quality of data in...