Indole-3-acetaldoxime (IAOx) is an important intermediate in the biosynthesis of several plant secondary metabolites. It is a precursor of several cruciferous phytoalexins (e.g. brassinin and camalexin), as well as of indole glucosinolates (glucobrassicin) and the plant hormone indole-3-acetic acid. Previous work showed that the plant pathogen Sclerotinia sclerotiorum transformed IAOx to indolyl-3-acetonitrile using an indolyl-3-acetaldoxime dehydratase, IADSs. In this work, IAOx activity was screened in mycelia from different crucifer pathogenic fungi. Leptosphaeria maculans isolate Laird 2 metabolized IAOX and mycelial cell-free extracts showed the highest activity among the tested pathogens. Partially purified indolyl-3-acetaldoxime dehydratase showed Michaelis–Menten kinetics, had an apparent molecular mass of 40 kDa and maximum activity at pH 6.5 and 22-25 0C. Sodium dithionite was used in all enzyme assays, and enzymatic activity was enhanced under anaerobic conditions in the presence of dithionite. The enzyme was stabilized in the presence of detergents and glycerol; however, it was strongly inhibited by dithiothreitol and antiproteases. On the basis of its substrate specificity, the enzyme appears to be an indolyl-3-acetaldoxime dehydratase similar to IADSs. Partial purification, stabilization and substrate specificity studies of IAD from Laird 2 will be described and results compared with previous work.