Corn naturally contaminated with 2,000 ppb total aflatoxin was adjusted to 17% moisture and ammoniated (Am) with 1.5% (w/w) anhydrous ammonia in an attempt at detoxification. The ammonia treatment reduced the detectable concentration to 510 ppb total aflatoxins. Ninety-six male Sprague-Dawley rats (75 g avg) were randomly divided into eight treatment groups with 12 rats per treatment. A fortified 12%-protein corn-soybean meal diet served as the control (C) diet. The corn used in the C diet contained no detectable aflatoxin. Treatment 2 contained 1,670 ppb aflatoxin; treatments 3 and 4 were similar to treatments 1 and 2, respectively, except the corn used was ammoniated. Treatments 5 through 8 contained 830, 420, 210 and 100 ppb total aflatoxin, respectively. Liver weights expressed as a percentage of final live weight were increased (P less than .05) in rats consuming diets containing 1,670 ppb aflatoxin compared to the other treatments. Serum albumin, IgG and IgM concentrations were not affected by ammoniation or by concentration of aflatoxin in the corn. At the end of 4 weeks, total serum protein was increased (P less than .05) in rats consuming diets containing aflatoxin-contaminated (AfC) corn and Am corn compared to those consuming the C diet. Average daily gain and average daily feed consumption were reduced (P less than .01) in rats consuming the diet containing 1,670 ppb aflatoxin. The growth of rats consuming AfC corn that was Am was equal to that of rats consuming a similar concentration of aflatoxin by dilution. From these results and the results of others, it appears that ammoniation of corn contaminated with aflatoxin may be a practical and economical method for detoxification.