Both countries have each released more than 200 prisoners under a deal sponsored by the United Arab Emirates.
Russia and Ukraine have exchanged hundreds of prisoners of war in the biggest single release of captives since the conflict began in February 2022.
Ukrainian authorities said 230 Ukrainian prisoners of war returned home in the first exchange in almost five months on Wednesday.
Russia’s defence ministry said 248 Russian servicemen have been freed on the same day under the deal sponsored by the United Arab Emirates (UAE).
Ukrainian President Volodymyr Zelenskyy has thanked the “warriors on the frontline who take the occupiers prisoner and replenish our exchange fund”.
He added: “The more Russians we take prisoner, the more effective negotiations on exchanges will be.”
The UAE’s foreign ministry attributed the swap on Wednesday to the “strong friendly relations between the UAE and both the Russian Federation and the Republic of Ukraine, which were supported by sustained calls at the highest levels”.
The UAE has maintained close economic ties with Moscow despite Western sanctions and pressure on Russia after it launched its invasion.
Ukraine’s human rights ombudsman, Dmytro Lubinets, said it was the 49th prisoner exchange during the war.
Some of the Ukrainians had been held since 2022. Among them were some of those who fought in milestone battles for Ukraine’s Snake Island and the city of Mariupol.
Russian officials offered no other details of the exchange.
The Russian military meanwhile said it had shot down 12 Ukrainian missiles over Russia’s southern Belgorod region bordering Ukraine.
Belgorod governor Vyacheslav Gladkov said the situation in the regional capital, also called Belgorod, “remains tense”.
The city came under two rounds of shelling on Wednesday, he wrote on Telegram.
“Air defence systems worked,” he said, promising more details about possible damage after inspecting the area later in the day.
Belgorod, which has a population of around 340,000 people, is the biggest Russian city close to the Ukrainian border. It can be reached by relatively simple and movable weapons such as multiple rocket launchers.
On Saturday, shelling in Belgorod killed more than two dozen people.
The attack was one of the deadliest on Russian soil since Moscow’s full-scale invasion.
On Monday, Mr Putin lashed out at the Belgorod attacks.