This study was conducted to evaluate the effect of dietary administered delta-aminolevulinic acid (ALA) and vitamin C on the hematological profiles and performance of sows and sucking pigs and to determine if iron status could be improved by dietary administration of ALA. Seven days before parturition, 120 sows (Landrace x Yorkshire) were randomly assigned within parities to 1 of 4 dietary treatments. The lactation treatments were arranged as a 2 x 2 factorial with 2 ALA concentrations (0 or 10 mg/kg of feed, as fed) and 2 vitamin C concentrations (0 or 500 mg/kg of feed, as fed). After farrowing, daily feed allowance increased gradually, and sows had ad libitum access to feed by wk 2. Sows provided diets with ALA tended to consume more feed (P < 0.10) than sows fed diets that did not contain ALA. Conversely, backfat losses were less in sows that received the diets with ALA compared with those received the nonsupplemented diets (P < 0.05). Supplementation with ALA and vitamin C resulted in improved hematological profiles (total protein, albumin, and IgG) in sows (P < 0.05). The iron status in the blood and milk were also improved by ALA supplementation (P < 0.05). Moreover, the BW at weaning and the ADG during the sucking period increased in response to supplementation of ALA and vitamin C (P < 0.05). The blood iron status of piglets was also improved by ALA supplementation (P < 0.05). In conclusion, dietary supplementation of ALA can increase the blood iron status of sows and sucking pigs, as well as the iron transfer efficiency from sows to piglets through elevated milk iron concentrations.