RNA - Activists have called for a boycott of what they describe as "farce" elections, raising doubts about the credibility of the polls, al Jazeera reported.
The government says the elections are democratic.
The polls opened at 8am local time (05:00 GMT) and are set to close at 8pm (17:00 GMT).
Bahrain'sAl Khalifa family has kept a lid on dissent since the opposition staged a failed uprising in 2011. Saudi Arabia sent in troops to help crush the unrest in a mark of concern that any power-sharing concession by Bahrain could inspire Saudi Arabia's own Shiite minority.
Bahrain, which is home to the US Navy's Fifth Fleet, has closed the main opposition groups, barred their members from running in elections and prosecuted scores of people, many described by human rights groups as activists, in mass trials.
"Clearly, legislatures from the world's leading democratic states believe that the upcoming election in Bahrain lacks legitimacy. You simply cannot crush, torture and imprison your entire opposition, call for a pseudo-election, and then demand the respect of the international community," said Sayed Ahmed Alwadaei, director of the UK-based Bahrain Institute for Rights and Democracy (BIRD).
The government said 506 candidates are running in the election, including the highest number of female candidates. It expects a higher voter turnout than in 2014, which it put at 53 percent, when opposition groups boycotted the elections.
Only 23, out of 40 incumbents of the House of Representatives, are seeking re-election this year to parliament, which has limited powers.
Many of Bahrain's Shiite say they are deprived of jobs and government services and treated as second-class citizens in the country of 1.5 million.
Human Rights Watch said in a statement that Manama is failing to create conditions necessary for a free election by "jailing or silencing people who challenge the ruling family" and banning all opposition parties.
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