Rim je nedvomno zaznamoval Bratinovo politično delovanje. Leta 1992 je bil namreč izvoljen za senatorja na listi Demokratske stranke levice (Partito democratico di sinistra - PDS). Zatem je bil leta 1994 ponovno izvoljen na listi Progresistov, leta 1996 pa na listi Oljke. V času svojega delovanja v italijanskem parlamentu je bil Bratina član odbora za zunanjo politiko v senatu, član italijanske delegacije v Svetu Evrope in član italijanske delegacije v skupščini Zahodnoevropske unije.

The confirmation of Darko Bratina's political-institutional commitment crossed the Capital. In 1992 he was elected Senator of the Republic with the PDS. He was elected again in 1994 in the list of the Progressives and in 1996 with the Olivo party. Among the various parliamentary appointments, Bratina was a member of the Senate Foreign Commission, the Italian Delegation to the Council of Europe and the Italian Delegation to the WEU Assembly.