Bisphenol A (BPA), a chemical component used in the manufacture of plastics, is commonly introduced to and detected in aquatic environments. This is the first study conducted to understand the distribution of BPA in the marine and freshwaters of Turkey. The purpose of this study is to report BPA concentrations measured from a time-series conducted in coastal waters of Erdemli and regional rivers located in the northeastern Mediterranean region. Furthermore, seawater samples obtained from other Turkish coastal areas-The Black Sea, Bosphorus, Sea of Marmara, and the Mediterranean Sea-also were investigated to gain a better understanding of regional and seasonal variations of BPA concentrations in Turkish Seas. Whilst spatial variation in BPA concentrations was very low, temporal variation was found to be high. It has been shown that BPA can reach the deep sea environment (> 500 m depth). This study indicated that BPA contamination has reached serious levels at another location in the world.