Niyazov made the announcement at the annual session of the Halk Maslahaty, or People's Assembly, in Ashgabat.
The prisoners include nearly 260 foreign nationals, including Afghans, Iranians, Turks, and Russians.
Niyazov regularly amnesties prisoners. Such amnesties are usually timed to coincide with national holidays. Turkmenistan is currently preparing for Independence Day celebrations on 27 October.