The Aspergillus flavus and aflatoxins are known to be detrimental to plant and animals affecting their productivity and yield. This study evaluated effects of toxigenic A. flavus and aflatoxins on physical parameters like seed germination, seedling vigor, root length, shoot length and also biochemical parameters like chlorophyll content, protein, sugars and amylase activity in sorghum seeds. The sorghum seeds were treated with 100, 250 and 500 μg ml-1 concentrations of
aflatoxins and likewise, A. flavus spore suspension adjusted to 1x108 spores ml-1 were also treated to seeds in different treatments. The experimental results revealed maximum inhibition of seed germination, seedling vigor, chlorophyll, proteins, total sugars and α-amylase activity in the sorghum seedlings was observed at 500 μg ml-1 followed by 250 and 100 μg ml-1. But seed treatment with toxigenic A. flavus spore suspension showed slight inhibition all the above parameters tested when compared to untreated control, but there was no significant decrease was observed. The study highlighted negative effects of the A. flavus and aflatoxins on the tested seed quality parameters tested there by necessitating need of monitoring of toxigenic fungi and their metabolites in sorghum seeds.