Prime Minister Ehud Olmert, Defense Minister Amir Peretz and IDF Chief of Staff Lit.-Gen. Dan Halutz have been interviewed by the committee.
Yadlin arrived at the meeting carrying a briefcase. Committee member Prof. Ruth Gavison said that she is "happy to start the day with work."
The committee is tasked with probing the military and political echelons' management of the war.
On Tuesday it was reported that the committee's discussions would be open to the media unless they are judged to be harmful to the state's security.
Foreign Minister Tzipi Livni is expected to appear before the committee on Thursday.
On August 28, 14 days after the war's end, Olmert announced his plan to appoint a government committee to probe the war in Lebanon.
The Winograd committee has been granted extensive powers by Acting Justice Minister Meir Sheetrit.
The committee has the power to set the scope and span of the probe.
Ministers and civil servants are obligated to appear before the committee if required to do so.
Aviram Zino contributed to this report