Background: Nano composites are widely used in medical sciences recently. Identification of chemical mutagens is an important issue in drug safety. Objectives: The aim of this study was to investigate mutagenicity and antibacterial activity of various generations of poly (amid amine) (PAMAM) dendrimers and agonic acid poly (amid amine) (PAMAM) Nano composite G2 on enteric pathogenic bacteria. Materials and Methods: Disc diffusion method, MIC (minimum inhibitory concentration) and MBC (minimum bactericidal concentration) determination were performed for antibacterial activity survey. Mutagenic properties were determined by Ames assay. Results: Various dilutions of PAMAM generations (G2, G3, G4 and G5) and agonic acid PAMAM Nano composite G2 had antibacterial effect on Escherichia coli, Salmonella enterica, Salmonella typhimurium, Enterococcus faecalis and Staphylococcus aureus. In Ames assay, reverted colonies were increased by PAMAM generations increasing. Moreover, reverted colonies Ames assay were lower when Nano composite G2 was applied. Conclusions: PAMAM generations and agonic acid PAMAM Nano composite G2 contain compounds with therapeutic potential and antibacterial characteristics, which can be used in medicine. Because some chemicals have mutagenic and carcinogenic properties, identification of these chemical is of great importance.