The Seimas Plenary Chamber is the principal workplace for the legislators, where Seimas sittings are convened ever since the autumn session of 2007.

The Chamber, ranking among the most modern plenary chambers in the European Union, opened its doors following the reconstruction of Building 2 of the Seimas in 2006–2007. Designed by architects Algimantas Nasvytis, Vytautas Nasvytis, Juras Balkevičius and Artūras Burba, the Chamber occupies the total area of 588.8 square metres and is 9.7 metres high.

The Chair of the sitting of the Seimas hits the gong to announce the adoption of a law, as well as the beginning and the end of a sitting. A bell is sounded to bring MPs to attention.