A disease outbreak occurred during the spring of 2009 among cultured juvenile European turbot (Psetta maxima) kept in growout tanks. During the outbreak, 10% of the turbot died. Typical clinical signs were unilateral exophthalmia and skin ulcers beneath the lower jaw. No bacteria were isolated from the fish. Based on a parasitological examination of the skin and fins, Philasterides dicentrarchi was identified to the species level. The infestation was treated with formaldehyde and, as an alternative, vinegar.