In this study, sublethal effects on the Mediterranean mussels (Mytilus galloprovincialis L.) collected from the Aegean coast of Turkey were determined. Enzymes such as glutathione-S-transferase (GST), superoxide dismutase (SOD), catalase (CAT), and acetylcholinesterase (AChE), metallothionein (MT) mRNA expressions, thiobarbituric acid reactive substances (TBARS) contents, determination of 14 heavy metals and micronucleus frequency were selected as multibiomarkers. Results show that heavy metals and an increase in the level of MT gene expression have been determined in tissues of mussels collected from all stations. The GST, SOD and CAT enzymes were increased in mussels of Aliaga and Old Foca, compared to the mussels of Urla, while it was showed inhibition at AChE levels. Extensive LP is determined on mussels of Aliaga. It was determined that mussels in Aliaga region have exposed more oxidative stress than Old Foca and Urla. These biomarkers were carried out for the first time in these stations to assess environmental quality.