LSDP members will be able to cast their votes from noon to 8 p.m. on Thursday, from 10 a.m. to 7 p.m. on Friday and from 10 a.m. to 2 p.m. on Saturday, the party said.
Some 9,723 members, or almost 48 percent, turned out for the first round of the election two weeks ago.
Paluckas received 41 percent of votes, the most among the five candidates who ran in the first round, had a lead of over 300 votes over Sinkevicius, who came in second with 37 percent.
The new chairman will take up the post on May 6.
Algirdas Butkevicius, the incumbent chairman, is not seeking re-election following the party’s poor showing in last autumn’s general election. The LSDP finished third in the election with only 17 seats in the 141-member Seimas.
The Social Democrats are electing their leader in a direct election for the first time. Its chairpersons were until now elected by the party’s congresses.