The metabolism of iprovalicarb in soil under aerobic conditions has been studied using the phenyl- and the valine-labelled parent substance. The investigations were performed in the dark, in a number of soils at temperatures of 20°C and with one soil at a temperature of 10°C. Under aerobic conditions in the dark iprovalicarb degraded to the final degradation product carbon dioxide. In parallel to mineralisation, bound residues were formed. Three metabolites were identified in the soil along with the parent compound and 14CO2. The major metabolites (> 10% of the applied radioactivity) were SZX 0722- carboxylic acid (M03) and PMPA M10), which were both degradable under aerobic conditions. Terephthalic acid (M23) was found as minor metabolite. Unextractable residues reached 29.5 to 33.9% of AR at study end (valine-label, day 21) and up to 27.9% of AR and 31.5% of AR (phenyl-label, 20°C, day 100 / day 365). Iprovalicarb was metabolised to the endpoint CO2 via two routes. In one route the breakdown of the molecule started with the cleavage of the amide bond between the L-valine and PMPA moieties. This led to the main metabolite PMPA (M10). The other route proceeded via oxidation of the methyl group on the phenyl ring to a carboxylic group (SZX 0722-carboxylic acid (M03)) and further oxidation.