The structure of the nervous system in the metacercaria of Clinostomum giganticum has been studied, using the methods of Gomori 1952 and Holt and Withers 1952 for the detection of acetylcholinesterase and non-specific esterase activities respectively. The nervous system of the metacercaria possess paired cerebral ganglia connected by the cerebral commissure, and three anterior and three posterior pairs of longitudinal nerve strands. The anterior and posterior nerves of corresponding pairs are connected by transverse commissures. There are twenty seven commissures in the whole body. The commissures are joined by numerous additional anastomoses giving the appearance of a dense net of nerve fibres.