Last week, the European parliament said European governments and secret services had accepted and concealed secret U.S. flights carrying suspects across the continent.
Council of Europe investigator Dick Marty said in a report last year that Romania and Poland, staunch allies of the United States, ran covert detention facilities for the Central Intelligence Agency.
"We found no solid argument to make us believe that the CIA was running illegal transports of prisoners," Norica Nicolai, the head of Romania's senate commission told reporters at the end of a year-long investigation.
"Our response is 'no' to allegations that CIA had secret detention facilities in Romania. We also respond 'no' to queries that Romanian institutions might have taken part in an operation of transferring detainees."
Nicolai said the commission had investigated 43 flights suspected of carrying detainees and assessed several Romanian airbases deemed to be stopovers or secret CIA rendition centers in reports by non-governmental organizations and media.
The report will be debated by the Romanian parliament next week, before being sent to European legislators.
European Union lawmakers backed a final report last week concluding a year of investigations into allegations that the CIA secretly held terror suspects in Europe and flew some to states where torture is used.
In his report, Marty said over 20 mostly European countries had colluded in a web of secret CIA jails and flight transfers of terrorism suspects stretching from Asia to Guantanamo Bay.