The first finding of the brittle star Amphiura securigera (Echinodermata: Ophiuroidea) in the Tyrrhenian Sea is reported. According to literature data, biotopic and edaphic features of the bottom indicate that this species preferentially lives in detritic mud-free biotopes characterized by good water circulation. Present data show that in the Mediterranean Sea A. securigera extends its bathymetric range as far as the circalittoral and upper bathyal floors.