Purpose. Feed production and excretion of nutrients by the animals are major sources of the environmental impacts of pig production. New communication and information technologies (NTIC) allow the development of precision feeding (PF) in pig-fattening units, which appears as a promising way to decrease environmental impacts of pig production. Therefore, we performed a life cycle assessment (LCA) of pig production with either conventional or PF applied to growing-finishing pigs. Methods. Two sources of data were involved: experiments and simulations performed using a model of pig fattening. A first experiment compared two-phase (2P) ad libitum (AdLib) feeding to ad libitum PF. A second experiment compared 2P restricted (Res) feeding to restricted PF. With the model, four feeding programs – 2P, 2PLCP (2P with low crude protein content), MP (daily multiphase group feeding) and PF – were simulated according to two feeding levels: AdLib and Res. A cradle-to-farm gate LCA was performed for each strategy, with the kg of live pig at farm gate being the functional unit. Five categories of impacts were evaluated: ILCD climate change (CC), ILCD acidification (AC), CML 2001 eutrophication (EU), CML 2001 land occupation (LO) and CED V1.8 non-renewable and fossil energy demand (CED). Results and discussion. PF slightly increased feed conversion ratio (FCR) and total feed intake compared with their reference 2P strategies, excepted in the in vivo experiment comparing PF-AdLib to 2P-AdLib. In this latter case, FCR was improved with PF. PF resulted in reduced N intake and N excreted relatively to 2P feeding in both in vivo and virtual experiments, whatever the rationing plan applied. PF always decreased AC and EU by reducing nitrogen excretion. With experimental data, CC was reduced in PFAdLib but not in PFRes compared to their respective 2P strategies. Simulated results showed a decrease in AC, EU and LO impacts, but not in CC, what is probably due to the small difference in total feed consumption between ad libitum and restrictedly-fed pigs (5 kg/pig). Conclusions. PF can reduce environmental impacts of pig production, particularly AC, EU and LO. Nevertheless, the definition of constraints on amino-acid and crude-protein contents and feed formulation should be made in accordance with local practices (i.e., feeding level) in order to obtain environmental gains expected with PF.