Low crude protein (CP) diets reduce nitrogen (N) born environmental impacts in pig production. Newly available feed-grade amino acids allow to reduce dietary CP to seldom tested levels, with balanced diets. The objective of this trial was to test the effect on growth performance, N balance, carcass composition and meat quality of CP reduction permitted by L-Ile and L-His supplementation. Twenty-four pens of 3 barrows and 3 gilts were fed ad libitum one of three soybean meal-corn based dietary treatments. Control CP levels in the four feeding phases (25-50 kg, 50-80 kg, 80-100 kg and 100-135 kg) were 180, 161, 143 and 126 g/kg. Treatments were 12 and 24 g/kg CP reductions, in all phases. Bodyweight (BW) gain and feed intake (FI) were recorded for each phase. Body composition was analysed by two-photon X-ray absorptiometry (DXA) in one pig per pen at the beginning and end of the trial. Carcass parameters were measured at the slaughterhouse for all pigs. Longissimus dorsi samples were taken for meat quality analysis 24 h after slaughter for two pigs per pen. A general linear model was used to test the effect of CP reduction. Dietary CP did not affect FI (2.86 vs 2.93 vs 2.93±0.12 kg/d, P=0.34), BW gain (1.18 vs 1.19 vs 1.16±0.04 kg/d, P=0.42), or feed conversion ratio (2.73 vs 2.81 vs 2.76±0.10, P=0.11). N intake was linearly decreased by 6.7% between treatments and N excretion by 11% (P<0.001). N efficiency was linearly improved by 2.8 percentage points between treatments (P<0.001). Carcass composition was not affected: DXA fat (20 kg; P=0.91) and lean (56 kg; P=0.44) deposition, carcass weight (109 kg, P=0.39), muscle depth (67 mm, P=0.13), backfat thickness (21 mm, P=0.93) and meat percentage (59.9%, P=0.87). Meat colour, intramuscular fat and pH at 24 h were not affected (P>0.1) but drip loss tended to increase (P=0.054) with CP reduction. In this trial, a 24 g/kg CP reduction efficiently decreased N excretion while maintaining performance and carcass and meat quality.