The global demand for protein is growing and it seems mandatory to find alternatives to animal proteins that are of good nutritional quality, implying a good digestibility. Legumes are potential candidates, as their indispensable amino acid (IAA) profile is relatively balanced. The aim of this study is to compare the protein and AA ileal digestibility of pea protein and casein in humans using ileal sampling and intrinsically labelled proteins. The first results were obtained on 7 subjects that were given pea protein (N = 3) or milk casein (N = 4). The mean ileal flow for all the volunteers was 1.83 ± 0.70 mL/30 min (mean ± SD), and was quite stable over time. The total N exogenous flow was 15.50 ± 5.83 mmol for pea protein and 13.56 ± 3.48 mmol for casein. The true ileal N digestibility was 95.40 ± 1.73% for pea protein and 95.42 ± 1.17% for casein. Ileal IAA digestibility is in progress. The intermediate results show no difference between pea protein and casein in terms of ileal digestibility, suggesting that pea protein could be a promising plant-based alternative. AA digestibilities and data from the remaining 9 volunteers to be tested will complete the study. Roquette.