Murat Karayilan, chief of the PKK's armed wing, said the withdrawal would begin May 8 and be monitored by independent observers.
If Turkey attacks PKK members during the withdrawal, Karayilan said, the group willl use "its legitimate right to self-defense."
Karayilan said the withdrawal had been made possible through the "unique efforts" of Ocalan, who has been imprisoned on an island in the Sea of Marmara for 14 years.
The withdrawal "will pave the way for the restoration of peace in the Middle East," Karayilan said. "The successful completion of this historic dream is a common objective for all of us who want peace, fraternity, democracy and freedom."
Turkey, the European Union and the United States list the PKK as a terrorist organization.
More than 50 journalists were transported under secretive conditions to a PKK stronghold in the Kandil Mountains. Cellphones were collected and television crews were not allowed to make live broadcasts.