Of the four rivals standing this time, none are expected to pose a threat to the president and his ruling PDGE, which holds all but one seat in a 100-seat parliament.
"There is no credible opposition to speak of," said IHS Global Insight analyst Kissy Agyeman-Togobo. "Obiang is assured victory, perhaps even increasing upon his 2002 win."
The capital Malabo was calm in the days ahead of the vote, residents there said. Traffic was restricted by ministerial order and police and soldiers guarded main roads and shops.
Voting starts at 8 a.m. (0700 GMT), with initial projections due after voting ends around 6 p.m. (1700 GMT).
While there are growing concerns over human rights in the country of some 650,000, Obiang's drive to turn Equatorial Guinea into a major energy player has met with some success.
Long a magnet for U.S. oil companies, the country has secured deals with Germany's E.ON Ruhrgas, Spain's Union Fenosa and Portugal's Galp Energia as part of its plans to become a regional gas hub too.


