The musculature of cercariae, pre-ovigerous and ovigerous adults of Diplodiscus subclavatus was studied by means of TRITC-conjugated phalloidin staining of filamentous actin and confocal scanning laser microscopy. The body wall appears to include four muscle layers: circular, outer longitudinal, diagonal and inner longitudinal. Two layers of longitudinal muscle fibers are arranged in a different mode due to the secondary transformed paramphistomid body construction. The organization of the acetabulum turned out to be more complex than ever described, with a radial, two layers of circular, two layers of meridional, an additional starry layer of muscle fibers and a few separate muscle layers of the accessory sucker. Within the pharynx was found a group of alar muscle fibers, never described before for any paramphistomids, and some morphological features, which were considered not to be characteristic for D. subclavatus (namely – the middle semicircular layer and the transverse muscle fibers in the pre-sphincter