More than 260,000 police have been deployed to protect the 50,000 polling booths set up across Africa's largest country, where 23 million Algerians are eligible to vote in a contest between six candidates after polling opened at 8:00 am (0700 GMT).
The 77-year-old president, who rose to power in 1999, is the firm favorite. But with warnings of electoral fraud and opposition calls for a boycott, the focus will be on turnout before polling stations close at 1800 GMT.