The survival of freezing in the Siberian earthworm Eisenia nordenskioeldi was tested under dry conditions and in frozen soil. Worms cooled under dry conditions to -4.5°C for 24 hours had a mean temperature of crystallisation of -3.5°C. The survival rate of animals exposed in frozen soil for 56 days was 50 to 82 % at temperatures between -4 and -10°C. After warming to summer temperatures, animals previously frozen produced viable egg capsules (cocoons). This is the first evidence for freeze-tolerance in an earthworm species.