This study describes the first isolation of Staphylococcus epidermidis from gilthead sea bream (Sparus aurata), reared in the southwest of Turkey. During the spring of 2003 (April-May), the infection appeared in juvenile gilthead sea bream (3-5 g) in a net cage. The outbreak occurred after a sudden increase of water temperature in the middle of April. The fish losses were up to 12% in one day. Affected fish showed haemorrhages on the fins and gills, the liver was anaemic and the abdomen was slightly distended as a result of ascitic fluid in the abdominal cavity. The gram-positive S. epidermidis was isolated from the anterior kidney, spleen and liver of sick fish. S. epidermidis was identified by morphological, physiological and biochemical features, using conventional methods and the ID 32 Staph system.