Technical Abstract: Maize (Zea mays L.) germplasm lines Mp718 (Reg. No. GP-xxxx, PI 662045) and Mp719 (Reg. No. GP-xxxx, PI 662046) were developed and released by USDA-ARS in cooperation with the Mississippi Agricultural and Forestry Experiment Station, Mississippi State, Mississippi, as sources of resistance to aflatoxin accumulation. Aflatoxin is a potent carcinogen produced by the fungus Aspergillus flavus Link: Fries that occurs naturally in maize. Mp718 and Mp719 were developed from a cross between Mp715 (PI 614819) and Va35 (PI 587150). These lines were evaluated for resistance to aflatoxin accumulation and mid-silk in a series of eight experiments conducted in Mississippi from 2004 through 2010. Aflatoxin accumulation was higher in Mp718 than in Mp719, but neither line differed significantly from Mp715. Mp718 and Mp719 reached mid-silk 13 d earlier and sustained less lodging than their resistant parent, Mp715. In an evaluation of single crosses, both Mp718, designated as Mp04:96 during development, and Mp719, designated Mp04:97, exhibited excellent levels of resistance to aflatoxin accumulation in crosses with NC388. The levels of resistance to aflatoxin accumulation exhibited by Mp718 and Mp719, when evaluated as both germplasm lines per se or in single crosses, indicate that Mp718 and Mp719 could be reliable sources of resistance for maize breeding programs.