LCA has been used in many studies to evaluate the effect of feeding strategy on the environmental impact of pig production. However, because most studies have been conducted in Europe the question of the possible interactions with the context of production is still in debate. The objective of this study was then to evaluate these effects in two contrasted geographic contexts of production, Brazil and France. The LCA considered the process of pig fattening, including production and transport of feed ingredients, feed production and transport to the farm, raising of fattening pigs, and manure storage, transport and spreading. Impacts were calculated at the farm gate and the functional unit considered was one kg of body weight gain over the fattening period. Performances of pigs were simulated for each scenario using InraPorc® population model (2000 pigs for each scenario considering between animal variability). The LCA calculations were performed for each pig according to its own performance and excretion, and the results were subjected to variance analysis. The results indicate that for some impacts there are clear interactions between effects of feeding program, origin of soybean and location of production. For climate change, the interest of phase feeding and incorporation of feed-use amino acids (FU-AA) is very limited and even counterproductive in Brazil with soybean from South, whereas it appears to be an efficient strategy with soybean from Center West, especially in Europe. Rather similar effects are observed for cumulative energy demand. Conversely, eutrophication and acidification potential impacts are reduced by phase feeding and FU-AA addition in a rather similar way in all situations. In all situations, precision feeding, the only strategy that takes account for the between animal variability, is the most effective approach for reducing life cycle impact of pig fattening, whereas the potential of phase feeding program and FU-AA is dependent of soybean origin and geographical context of pig production, contrasting with many published results.