All PNG citizens over the age of 18 years who have enrolled to do so are entitled to vote at national and provincial elections. (The voting age was lowered from 21 to 18 for the third House of Assembly elections in 1972.)
Voting is not compulsory but the turnout for each election has been over 65 percent. Candidates for office must be citizens over the age of 25 years who have not been found guilty of violating the Leadership Code in the previous three years or violating the election laws in the previous nine months. Elections are supervised by an Electoral Commissioner and officers of the Electoral Commission. Violence and accusations of vote rigging have been a feature of all elections, but in spite of some well documented instances of malpractice elections have been relatively honest. Under the 1975 Constitution, elections are to be held at least every five years but on three occasions governments have been overturned by votes of no confidence held in the House of Assembly. In 1991 the Namaliu Government introduced reforms to improve electoral procedures and reduce voting irregularities.
There has been a high turnover among parliamentarians. An average of 50 percent of members in each parliament have failed to be reelected. The number of candidates has increased at each election. Due to the large number of candidates and the preferential voting system successful candidates often have a very low percentage of the total vote. This trend is continuing. The 109 constituencies were contested by 879 candidates in 1977, 1,125 in 1982, and 1,513 in 1987. In 1977, 11 winning candidates received less than 1 percent of votes and 19 received over 50 percent. In 1982, 20 winning candidates received under 20 percent and 18 over 50 percent. In 1987, 40 winning candidates received less than 20 percent and only 7 more than 50 percent.