The peaceful protest, involving various NGOs and opposition parties, saw scores of people wearing anti-TPP t-shirts and holding placards warning against the mammoth trade deal.
While a few hundred gathered near the capital's Independence Square, around 3,000 others, mainly supporters of opposition Pan-Malaysian Islamic Party, marched to a nearby field to listen to speeches given by critics of the agreement.
Prominent Malaysian opposition figure Chua Tian Chang, better known as Tian Chua, told the crowd that the TPP will affect Malaysia's sovereignty and that ‘jobs will be reduced and prices of medicines will go up.’
‘This (TPP) will only help the rich people. It will not help the poor people in Malaysia and I don't see any benefits for my family and I,’ said Mohammad Noor Ismail, a student who attended the protest.
The TPP aims to create the world's biggest free-trade area including Canada, Brunei, Chile, Malaysia, Mexico, New Zealand, Peru, Singapore, Vietnam, the United States, Japan and Australia.
In October, 12 Pacific nations finally reached an agreement on the pact, a major diplomatic coup for Washington.
Both China and the United States are pushing their own free trade visions for the economically vibrant and populous region.
China is pointedly excluded from the TPP, part of Washington's attempt to ramp up influence in the region with its ‘pivot’ to Asia.
The trade deal will be formally signed in New Zealand next month, officials in Wellington said Thursday.
Following the signing, each country has two years to complete the ratification process before the trade accord takes effect.
Critics in the countries involved have vowed to fight ratification, saying it threatens labour rights and environmental protection.
The Malaysian government is widely expected to sign and ratify the deal according to reports.
In October, it had hailed the Pacific Rim trade deal as a boost for commerce, saying it won key concessions in areas including its controversial system of business preferences for its ethnic Malay majority.
Parliament is expected to debate next week whether the country should sign the accord which involves significant market openings from Canada, the United States and Japan, and establishes mechanisms to handle disputes between foreign investors and governments.
Malaysian opponents of the trade deal have criticised the secrecy of the talks and warned that the TPP could saddle consumers with higher medicine costs and provides too much protection for foreign companies.
US President Barack Obama has described the deal as a foundation for ‘21st century trade’.