A preliminary Life Cycle Assessment was performed for estimating the carbon footprint (CF) of the heavy pig production in eight fattening pig farms in Northern Italy. The average pig number in each farm was 1967 (±1379), the average number of pigs fattened every year was 4123 (±3349). Initial and final weigths were kg 38.2 (±11.0) and 167.1 (±5.25), respectively. System boundaries of CF study comprised the growing and fattening phase in the pork production chain; they did not include the sowpiglet phase, slaughtering and feed production. Environmental burden of purchased feeds and piglets was calculated with background database values and was comprised in CF estimation as indirect carbon dioxide equivalent (CO2eq) emissions. Functional unit (FU) was 1 kg of body weight at the farm gate. The global warming potential (GWP) was expressed as kilograms of CO2eq; greenhouse gases (GHG) considered in this analysis were CH4, N2O and CO2 with a GWP of 25, 298 and 1 kg CO2eq respectively. The average CF of one FU was 3.83 (±1.07) kg CO2eq. The contribution of each emission source was: enteric CH4 3.34%, manure CH4 17.7%, manure N2O 1.38%, direct soil N2O 6.59%, indirect soil N2O 6.39%, direct CO2 1.00%, indirect CO2 63.6% (comprising production of purchased feed and piglets, fossil fuel extraction and refining, electricity production, and transportations). The results are consistent with those obtained in other studies carried out in Northern Europe or USA. In respect to other animal foods, such as milk, where the enteric fermentation is a main GHG source and the crop production is an important component of the system, this study showed that the main drivers of GHG production in growing and fattening phase of pork production chain are the off-farm feed production and transportation phase; on the contrary the activities within the system boundaries are of minor importance. Mitigation strategies should be addressed to feed production chains and manure management systems. This assessment should be considered preliminary because more differentiated data are expected from in-progress studies concerning feed production chains and piglet production phase.