The present study was undertaken to evaluate the in vivo genotoxicity of sulphanilic acid and its biodegradation product using mice as a model. 0.5 mg of sulphanilic acid at 24 hrs, 48 hrs and 72 hrs time interval and its aerobic treated product at 48 hrs time interval were injected to different mice. The experiments were carried out in control group after treatment with DMSO. The air drying preparations were made by dissecting out the limbs of adult mice and processing it. A highly significant increase in mean aberration values were found among all treated groups when compared with the control. Chromosomal aberrations observed were stickiness, clumping, breaks, dicentric, rings and gaps. Chromosomal aberrations were found both in control as well as treated groups of mice but the number of aberrations was significantly high in all treated groups as compared to control mice. Among treated groups, the number of chromosomal aberrations was high in mice treated with 0.5 mg of sulphanilic acid at 72 hrs. It has been proposed that toxins released by aromatic amines might have caused chromosomal anomalies by coming in direct/indirect contact with the chromosomes after the disintegration of nuclear membrane during cell division. Such chromosomal anomalies may lead to the genetic instability of mice population. From these findings we conclude that sulphanilic acid is more genotoxic in nature as compared to its aerobic degradation product. These degraded samples also induced significantly higher genotoxicity as compared to control but found to be less genotoxic as compared to parent aromatic amine.