The mechanism underlying proteoglycan (PG) absorption in the intestine is not clear. Hence we analyzed the transport of salmon PG in the rat jejunum, ileum, and colon by the everted-sac method. The jejunum showed the largest capacity for PG transport. Jejunal transport of PG was also greater than that of chondroitin A and C. An inhibitor of clathrin-mediated endocytosis reduced jejunal PG transport. We conclude that intestinal PG transport is highest in the jejunum, and is partially dependent on clathrin-mediated endocytosis.