Four cultivars of peanuts (Florigiant, Florunner, Starr and Tamnut) grown at two locations (Lewiston, North Carolina (NC) and Stephenville, Texas (TX)) in the National Regional Variety Trials were evaluated for protein nutritional quality. Peanuts, blanched with a minimum of heat treatment and partially defatted on a Carver press, were extracted with hexane at room temperature. Rats were fed these peanut meals to provide 10% of dietary protein (N × 6.25). PER was calculated as the ratio of weight gained to protein consumed for the 28-day feeding period. Adjusted PER values of the 8 peanut meals ranged from 1.3 to 1.7 compared to a value of 2.5 for the casein control diet. No statistically significant differences existed in PER among the 4 cultivars grown in NC. Florunner and Tamnut produced in TX had lower PER values than Florigiant and Starr grown at the same location. Florigiant, Florunner, and Tamnut grown in NC had lower PER values than the same varieties from TX. Rats were fed diets with Florunner peanut meal supplemented with methionine, lysine, and threonine, singly and in all combinations, for 7-day periods. Differences in protein quality between NC and TX-produced peanuts were overcome by addition of methionine to the diets. When all three amino acids were added, peanut meal from both locations supported growth of young rats equal to that of casein.