"Iran successfully launched a capsule, codenamed Pishgam (Pioneer), containing a monkey and recovered the shipment on the ground intact," said the statement by the defence ministry's aerospace department.
Al-Alam channel said the monkey was "alive" after travelling to an altitude of 120 kilometres (75 miles) for a sub-orbital flight.
Iran announced in mid-January it would try once more to send a monkey into orbit as part of "preparations for sending a man into space," which is scheduled for 2020.
Iran's space programme deeply unsettles Western nations, which fear it could be used to develop ballistic missiles capable of carrying nuclear warheads they suspect are being developed in secret.
Tehran has repeatedly denied that its nuclear and scientific programmes mask military ambitions.
Iran has previously sent a rat, turtles and worms into space.
Voice of Russia, RIA, AFP