Iranian ambassador to Kuwait Rouhollah Ghahramani Chabok arrived in El-Kuwait Monday morning, ISNA reported.
Iran has not appointed an ambassador to Kuwait for a year after recalling the previous ambassador Ali Jannati from Kuwait.
On Monday, Iranian Foreign Ministry Spokesman Ramin Mehmanparast said Iran and Kuwait would resume ambassadors' mission this week.
Iran said ambassadors of the two countries would return to their posts soon.
The measure came after a Kuwaiti criminal court in March accused two Iranian and one Kuwaiti individuals of espionage for Iran's Islamic Revolutionary Guards Corps (IRGC).
Iranian President Mahmoud Ahmadinejad rebuffed such accusations and said Iran was not operating spy ring in Kuwait.
Kuwait later recalled its ambassador to Tehran and expelled several Iranian diplomats following accusation of their involvement in the spy ring.
Iran expelled some Kuwaiti diplomats in retaliation.
Also Iranian Foreign Minister Ali Akbar Salehi has recently visited Kuwait and held talks with officials of the country.