A putative chorismate mutase (CM) gene, Ma-cm-1, was isolated from the nematode Meloidogyne arenaria. The predicted protein (named MA-CM-1) with amino-terminal signal peptides was significantly similar to CMs in M. javanica, M. incognita, Globodera pallida and bacteria. Secondary structure prediction of MA-CM-1 indicated that it also had the three conserved alpha-helix domains present in Escherichia coli CMs. RT-PCR analysis showed that Ma-cm-1 was transcribed in both the preparasitic second stage and early postinfection juveniles. In situ mRNA hybridization revealed that the transcripts of Ma-cm-1 accumulated specifically in the two subventral oesophageal gland cells of M. arenaria. The widespread existence of CMs in the sedentary endoparasitic nematodes indicates that this enzyme is a key element in the host–parasite interaction.