Qualitative and quantitative aspects of macrozoobenthic fauna in Edremit Bay were studied. Benthic samples were collected from 20 stations at depths ranging from 1 to 30m in October 2002. Salinity of sea water varied between 35.3 and 38.6psu, temperature between 18.8 and 21.6 degrees C, dissolved oxygen between 2.6 and 8.9mg/l, and silt-clay percentage of sediment between 1.6 and 94. 1. A total of 139 macrozoobenthic taxa were identified, of which Polychaeta was the dominant group (44.6% of species, 42.7% of specimens). Shannon -Weaver's Diversity Index (H'), Pielou's Evenness Index (P), Soyer's Frequency Index (F), Bray-Curtis similarity measure and Spearman's rank correlation coefficient were applied to the presence and abundance of the benthic fauna. Medium diversity index values (between 2.7 and 4.8) but high evenness index values (between 0.75 and 0.98) were determined in the area. The cluster and nMDS analysis showed that there were 6 distinct species assemblages in the area. A positive correlation was determined between silt-clay percentage, and number of individuals, number of species and diversity index value. The number of specimen is also positively correlated with depth.