The 21st Commonwealth heads of government meeting was declared open on Friday by Queen Elizabeth II here amid demands to take a tough stand against violation of human rights.
Vice president Hamid Ansari is representing India at the summit, which is also debating on tackling tough challenges posed by the global financial crisis, food security, climate change and trade.
It was an all-woman affair at the Perth Convention and Exhibition Centre when outgoing CHOGM chair and Prime Minister of Trinidad and Tobago Kamla Persad-Bissessar handed over charge to incoming chair, Australian Prime Minister Julia Gillard, in the presence of Queen Elizabeth II.
Bissessar highlighted the all-women character of the change at the top in her address to the biennial summit of the 54-nation grouping.
In her address, the Queen, who also heads the Commonwealth, asked the leaders gathered to keep the grouping "fresh and fit for tomorrow".
Underlining the relevance of the grouping, she said the "results of the meeting would have a global impact" and that they would be "positive and enduring".
Dressed in a powder blue silk jacquard dress by Angela Kelly, the Queen drove to the venue of the summit with people lining on either sides of the St Georges Terrace road waving flags and cheering as the motorcade rolled by.
People had gathered on the streets of Perth in large numbers with a public holiday being declared in view of the summit.
The opening event was also addressed by Australian Prime Minister Julia Gillard, who is the new chair, Commonwealth Secretary-General Kamalesh Sharma and outgoing chair Bissessar.
Gillard, in her opening speech, appeared to refer to the Lankan issue when she said it needed "to ensure that those member nations that fall short (of the group's values) understand that their peers want to see change".
Much of the debate has focused on Sri Lanka and international demands that it allow an independent inquiry into accusations of war crimes during its 25-year civil war, especially in its final months in 2009.