Electron spin resonance (ESR) spectroscopy was used to detect irradiated chicken eggs, to investigate the effect of irradiation dose on the ESR signal intensity and to identify the stability of radicals under 77 days of storage. Raw chicken eggs were irradiated with doses of 0, 0.5, 1, 2, 3 and 5 kGy at room temperature using a Co-60 irradiator. The samples were prepared by separating, drying and powdering shells from the raw eggs. The irradiated chicken egg shells presented an asymmetric absorption in shape at g₁=2.0023±0.00004 and g₂=1.9979±0.00005, different from the non-irradiated ones. The strength of the ESR signal increased linearly with the applied doses (to 5 kGy). The intensity of the ESR signals after irradiation were stable even after 77-day of storage at 5℃ and/or room temperature.