BACKGROUND: Poultry meat belongs to perishable foods and the major concern of food industries is the microbial spoilage of poultry meat. OBJECTIVES: The aim of present study was to investigate the effect of chitosan (CH) coating enriched with different concentrations of Ziziphora clinopodioides essential oil (ZEO) in comparison with control group on some of the sensory and microbial properties of chicken breast fillets during storage at refrigerated temperature for 12 days.   METHODS: Essential oil extraction was done by hydro-distillation method and its chemical composition was determined by gas chromatography with mass spectrometry (GC-MS). In the present study, chicken breast fillets separately were dipped in 2% CH solution containing ZEO at concentrations 0, 0.5 and 1% and then stored at refrigerated condition for 12 days. After that chicken fillets were studied at 7 intervals (0, 1, 3, 5, 7, 9 and 12 days) regarding microbial (Total mesophilic and Psychrotrophic bacteria, Pseudomonas spp. and Enterobacteriaceae) and sensory (color, odor and taste) examination. RESULTS: The most important compounds of the ZEO were geraniol (20.62%), carvacrol (18.17%), thymol (5.39%), α-terpineol (7.49%) and 4-terpineol (6.83%). Results of this study revealed that in the treatments coated with CH containing ZEO, total viable counts (TVC), Pseudomonas spp., lactic acid bacteria, Psychrotrophic bacteria and Enterobacteriaceae familysignificantly (P<0.05) decreased as compared to control group during the storage period. Based on the results of the present study, coating of chicken fillets with chitosan alone or chitosan containing 0.5 % concentration of ZEO showed better sensory properties. CONCLUSIONS: CH coating enriched with 0.5 % ZEO has potential to extend shelf life of chicken fillets without any unfavorable organoleptic properties.