Journalists, delegates and party members who were at the Congress had to struggle between sleeping and keeping vigil throughout the voting process, which started after 6:00 pm on Saturday.
This was after several speeches from the leadership of the party and other activities had taken place during the day.
Most of the delegates, who had traveled from long distances across the country, were seen either sleeping on chairs and on any available space they could lay their heads.
The NDC is holding the congress to elect new national executives to steer the affairs of the party for the next four years.
About 65 members of the NDC are contesting in the race, and over 9,000 delegates are taking part in the voting.