Mullus barbatus barbatus (Linnaeus, 1758) is a teleost fish with high commercial value in Algeria. 120 fish specimens of Mullus barbatus barbatus (L.) sampled from Algerian coasts were examined for their parasitic nematodes. Collected larvae were identified according to morphological and molecular analysis. Collected larvae belong to Hysterothylacium reliquens. This parasitic nematode is reported for the first time in Algerian coasts.