Male and female Japanese quail 21 weeks old, that were given total body doses of 60Co gamma-rays ranging from 0 to 30 Gy, showed a peak in mortality at 6-8 days post-irradiation. The LD 50/30 was 22.5 Gy, and the LD 90/30 was 26.7 Gy. No differences were evident in mortality between males and females. The reduction in egg production by 30 days post-irradiation was related linearly to the dose, for doses above 6 Gy. The reduction in egg weight (30 days post-irradiation laying period) was also related linearly to the dose.