Protesters will stage a rally outside the Presidential Palace before marching to the government building to hand a list of demands to officials.
Vilius Simutis of the Lithuanian pensioners' association Bočiai, the organizer of the rally and the march, told BNS that participants would remind the authorities of their promises to further raise pensions.
The average monthly old-age pension is planned to reach around 332 euros this year, up by 30 euros from late 2017.
"We want the government to deliver on its promise to increase pensions by 40 euros," Simutis said.
"We also demand that the state should not subsidize second-pillar pension funds from Sodra," he added.