Purpose The goal of this paper is to describe the life cycle inventory (LCI) approach to the cokemaking process in the Integrated Steel Plant’s Coke Oven Battery (ISPCOB) in Kraków, Poland. The system boundaries were labeled as gate-to-gate, covering the full chain process of coke production. The background input and output data from the coke production process (CPP) has been inventoried. Methods The functional unit (FU) was produced of 1 Mg of the coke in ISPCOB. The following inputs and outputs have been taken into account in the LCI study: product (coke), all intermediate products, by-products, and emissions. Raw fuel mining and means of external transportation of natural gas, manufacture of downstream products, their use, end of life, and infrastructure were not included. Time coverage is 2004, because since 2005, robust inventory data coverage of full ISP coke processes are lacking. Data used for inventory calculation are affected by uncertainty. Results and discussion With regard to 1 Mg of coke produced in ISPCOB in 2004, the consumption of coke coal and coke oven gas amounted to 1.35 Mg and 195 m3, respectively. The main materials, fuels, and energy used for the coke production were electric energy, steam, air, heat, and industrial water. Emissions of SO2, NO2, CO, CO2, NH3, aliphatic hydrocarbons, HCN, H2S, CS2, benzene, xylene, toluene, phenol, pyridine, dust, tar matters, Cr, Cd, Cu, Pb, Ni, and Mn have been considered. Conclusions The data for the LCI have been based on the year 2004. Uncertainty assessment in LCI is discussed. The purpose of this study is to help ISP authorities to solve environmental and technical aspects, as well as to train steel industry people in the field of life cycle assessment. Finally, presented LCI study for ISPCOB can serve as a representative data for LCA analysis of coke production in coke plants. Recommendations The impact assessment phase aims to present more understandable results from the inventory analysis, and life cycle impact assessment (LCIA) will be the direction for future research.