Some 14.4 million Malaysians cast their ballots in parliamentary elections on Wednesday.
The election is seen as a political battle between incumbent Prime Minister Najib Razak and nonagenarian former Prime Minister Mahathir Mohamad.
The polls officially closed at 5 pm local time (0900GMT), and early results are due to start trickling at about 6.30 pm (1030GMT).
Najib, the eldest son of the former Premier Abdul Razak, is the candidate of the ruling coalition National Front (Barisan Nasional).
Mahathir, Malaysia's longest-serving prime minister, is the opposition candidate. If he wins, the 92-year-old will become the world's oldest leader.
Independent pollster the Merdeka Center had predicted that the Barisan Nasional coalition will win 100 of the 222 seats in parliament, while Mahathir's alliance will win 83.