This study aimed to assess the effect of titanium dioxide (TiO2), Thyme essential oil, and a mixture of both on the quality of chicken fillets. Fresh chicken breast fillets samples were treated with TiO2 nanoparticles as a trial (T), Thyme oil (2%) as a trial (O) individually and in mix of both as a trial (M). All samples were examined during cold storage (4 ± 1 °C at zero, 2, 4, 6, 8, 10, 12 and 14 days from sensory, bacteriologically and chemical points of view. The results indicated a positive effect on the shelf life of treated samples as compared to untreated ones especially in trial (M). On the other hand, there was a good antibacterial activity of such treatment on APC, Psychrotrophic and coliform counts. Also, the results showed that pH, TBA and TVN values were increased but not reached to spoilage (6.4) in all Thyme oil 2% treated samples; which gave the best effectiveness followed by TiO2 and finally the combination of both Thyme oil 2% and TiO2