This study tested the hypothesis that pre-weaning supplemental arginine may have a carry-over effect on intestinal growth and development of piglets immediately after weaning. Fifty-four [Duroc × (Landrace × Yorkshire)] piglets were fed a milk replacer diet supplemented with 0 (control), 4, or 8 g kg^-1 of l-arginine from d 4 to 21 of age (6 replicate pens of 3 piglets per group). Piglets were then weaned to a common corn-soybean meal diet and fed for another 21 d. On day 42, 6 pigs per treatment were randomly selected for blood and tissue sampling. Arginine supplementation improved body weight of the piglets on d 42, average daily gain during d 22-31 (P < 0.05). Supplementation of 8 g kg^-1 arginine decreased feed:gain (F:G) ratio in piglets during d 22-31 (P = 0.010). Compared with controls, 8 g kg^-1 arginine improved villous height in duodenum, jejunum, and ileum; villous area in duodenum and jejunum; relative intestine weight; and plasma contents of insulin at d 42 (P < 0.05). Arginine supplementation increased mucosal protein content in all 3 segments of the small intestine (P < 0.05). These novel results clearly demonstrate a carry-over effect of pre-weaning supplementation with arginine on enhanced intestinal growth and development in the early post-weaning period.