One fishing cruise was performed in the N.Aegean Sea in July 1993, with the aim to study the mesopelagic fauna. Samples were taken from nine stations depth 250, 500, 750 and 1000 m using the METHOT midwater trawl. A total of 41 taxa were identified, from which only fishes were identified to species. The highest abundance of invertebrates was observed at 500 m, with the lowest value at 1000 m. Intermediate values were observed at 250 and 750 m. Euphausiaceae, followed by Chaetognatha, were the dominant taxa. Fifteen species of mesopelagic fishes were caught. About 90% of the sampled specimens were Myctophidae, which demonstrates the importance of this family to the ecology of the mesopelagic zone in the Aegean Sea.