It's the largest since the war began in February, involving almost 300 people.
Footage released by a PoW coordination team under Ukraine's defence ministry showed people being led away, in a location given as Chernihiv in north Ukraine.
Among those released by Moscow: the commanders who led a prolonged Ukrainian defence of Mariupol earlier this year.
In a video published by the Ukrainian President's office, Volodymr Zelenskiy was seen addressing via video link the released commanders, who are said to be in Turkey.
Also released: 10 foreigners.
Saudi Arabia helped broker an arrangement which saw the 10 flown to the kingdom.
According to the Saudi foreign ministry, the mediation involved Saudi Crown Prince Mohammed bin Salman, who has maintained close ties with Russian President Vladimir Putin.
The freed prisoners were American, British, Croatian, Moroccan and Swedish nationals, the ministry said in a statement.
The timing and scale of the swap came as a surprise.
Earlier in the day, Putin had announced a partial troop mobilization, in an apparent escalation of the conflict.
President Zelenskiy said the prisoner swap had been under preparation for quite a long time and involved intense haggling, with the help of Turkey and Saudi Arabia.
Under the deal, 215 Ukrainians were released - most of them captured after the fall of Mariupol.
In exchange, Ukraine sent back 55 Russians and pro-Moscow Ukrainians, including Viktor Medvedchuk, the leader of a banned pro-Russian party who was facing treason charges.
