Trawl samples were collected during two periods, autumn 1995 and winter 1996. A total of 2574 specimens per trawling hour (Nh‐1) composed of 105 species were collected in the Cyclades, while in the Saronikos the 1633 specimens (Nlr‐1) that were captured composed of 40 species. Species richness and the Shannon‐Wiener diversity index were higher values in the Cyclades. Higher diversity was recorded in the winter and in the 150–300 m depth zone in both locations. Similarity of the demersal fish communities in the two study areas were investigated using multivariate analysis. It appeared that the affinity of sampling sites, based on the composition of fish catches, was strongly influenced by depth.Trachurusspp (T.picturatusin shallow waters in autumn, andT. trachurusin deeper locations in autumn and in all depths in winter) dominated the Saronikos catches and contributed mainly to the dissimilarity that was displayed between the composition of the demersal fish communities.