Under aerobic conditions iodosulfuron was rapidly degraded in soil, with an aerobic half-life between 1 and 24 days. Iodosulfuron is mostly moderately mineralized. Nine metabolites were identified of them three accounted for more than 10% of the applied radioactivity, namely AE F059411, BCS-CW81253 and AE F075736. These three metabolites were considered as major compounds. AE F059411 is slowly degraded with a half-life between 200-300 days, whereas F075736 was moderately fast degraded with a half-life of 20-80 days and BCS-CW81253 was moderately fast degraded with a half-life of around 25 days. One additional metabolite, AE F145741, was observed as >5% AR at several sampling points, however only at low temperature incubation. Therefore, this pathway may prefer low temperature conditions. Other minor metabolites were AE 0000119, AE F161778, AE F145740 and AE 0002166. All minor metabolites had a half-life of maximally 150 days.