Half of Malaysia's 38 Cabinet ministers, and nearly 40 per cent of its MPs, are from Umno.
The country's grand old party leads the 13-party Barisan Nasional (BN) coalition in which each member, technically, has an equal voice.
However, Umno - formed in 1946, more than a decade before Malaysia gained its independence from Britain in 1957 - often holds sway on policy matters.
Some of the policy decisions are decided at Umno's annual general assemblies. That is why the annual gathering is the most closely-watched political event in Malaysia, Asean's third largest economy after Indonesia and Thailand.
Ironically, while it is a staunchly Malay nationalist party, Umno's acronym comes from its English-language name - United Malays National Organisation.
Umno is the biggest party in 222-seat Parliament, with 86.
The next biggest is the opposition Democratic Action Party, with 36 seats.
Percentage of Malaysia's MPs who are from Umno.
Number of members in the party.
Anyone with ambitions of becoming a senior Cabinet minister would do well to join Umno, which gets to decide who are given the choice posts in government, including those for prime minister, deputy prime minister, finance and home ministers.
Umno also decides on other top appointments - from who leads the country's myriad government-linked companies to village chiefs and imams (Muslim prayer leaders) for mosques in Umno-controlled states.
The party has three million members, in a country with a population of 32 million.
It also has an extensive network, with 191 divisions in 12 of the 13 states. Each division represents a parliamentary constituency.
Under these 191 divisions, there are nearly 22,000 Umno branches.
The only state where Umno does not have a presence is Sarawak, which has 31 seats in Parliament.
BN's interests in Sarawak are covered by the United Bumiputera Heritage Party and other allied parties.