A modified cotttonseed extraction and purification procedure was used to detect aflatoxins in samples of sunflower seeds. No aflatoxins (< 2 ppb) were detected in over 50 random samples taken from varied lots of commercial seeds on sale in central Virginia. No Aspergillus flavus-like or A. parasiticus-like organisms were seen in cultures of the natural flora of such seeds when grown on both whole and crushed seeds. No naturally occurring aflatoxins (< 2 ppb) were detected in the cultures. Standing cultures of crushed seeds, when inoculated with A. flavus ATCC 15548, resulted in 271 μg total aflatoxin/g medium within a 2 week period of growth at room temperature. The crushed seed cultures had the following ratios for B1, B2, G1, and G2: 12, 1, 17, and 3, respectively. Whole seed cultures tested about 25% lower than crushed cultures for total aflatoxin content but whole cultures did lack detectable levels of B2. The whole seed cultures had the following ratios for B1, B2, G1? and G2: 13, 0, 19, and 2. The increase in toxin levels in the crushed cultures for each type of toxin compared to the total increase was as follows: G1 increased 37%, B1 increased 29%, G2 increased 21%, and B2 accounted for 12% of the total increase. Black sunflower seeds, whole or crushed, will support the growth of A. flavus and the production of aflatoxins at levels that may approach that of rice medium but not that of coconut medium.