Diplostomum spathaceum (Rudolphi, 1819) and D. pseudospathaceum Niewiadomska, 1984 have been known
for a long time under two different names. The above mentioned two species are revised in this article, on the basis of
plenty of collected materials from fish farms in Kafr Elsheikh, Egypt. Variations of both fixed metacercariae (heat-fixed) and live ones were critically investigated on the basis of the morphologically and specific systematic organs. The
monographic data and the available measurement ratio which were obtained revealed a high similarity for the fixed
metacercariae. However, the comparison of the variations are not enough to separate them as two distinct species.
Consequently, D. pseudospathaceum could be recognized as a synonym for the D. spathaceum.