Today, weaner diets are optimised using digestibility coefficients obtained from grower-finisher pigs, which may overestimate the digestibility in weaners. The aim of this study was to evaluate the standardised ileal digestibility (SID) of CP and amino acids (AAs), and the intestinal morphology in pigs 0–4 weeks postweaning when fed different protein sources. The experiment included 128 pigs weaned at day 28 and the protein sources were wheat, soybean meal (SBM), enzyme-treated soybean meal (ESBM), hydrothermally treated rapeseed meal (HRSM) and casein. The experiment was conducted as a difference method study including wheat in all diets. Eight pigs were slaughtered on the day of weaning (day 0) and six pigs/treatment were slaughtered at days 7, 14, 21, and 28 postweaning. The SID of CP and AA, as average over the four weeks, was lowest for ESBM and highest for wheat and casein, with SBM and HRSM being intermediate. The SID of CP and AA increased (both linear and quadratic, P