Environmental pollution has been shown to haveadverse effects on all aquatic and terrestrial organisms including human beings. Chemicals such as nonylphenol (NP) and bisphenol A (BPA) are widely known with their abundance in the environment since they are commonly used as non-ionic additives in pesticides, herbicides, detergents, cosmetics, and plasticwares. It has been reported that these compounds may cause many different health problems including cancer. It is well known that the mutation occurred in DNA is the first step towards to the development of cancer. Therefore, the aim of this study was to determine the mutagenicity and non-mutagenicity of NP and BPA by using Ames /Salmonella/ Microsome Test method. Different doses of these chemicals with S9 (metabolic activated) or without S9 (non-metabolic activated) have been investigated in the TA98 and TA100 strains of Salmonella typhimurium. Results showed that non-toxic 100 µg/plate, 10 µg/plate, 1 µg/plate, 0.1 µg/plate doses were not mutagenic in the experiments performed in both strains