In the Bajaur by-election, a close race between PTI and ANP is anticipated.
Voting is scheduled to begin at 8 a.m. and run continuously until 5 p.m.
A representative for the province Election Commissioner said that 12 candidates are running, five of whom are independent and the other seven are members of political parties.
In the constituency, 107,910 people were registered to vote, 79,972 of them were female.
Pakistan Tehreek-i-Insaf and Awami National Party candidates are anticipated to face off in a fierce race.
Polling will take place in a calm environment thanks to strict security protocols. 23 polling places were identified as the most sensitive by the local authorities on Wednesday.
To thwart any attempts at sabotage, CCTV cameras had been placed at the extremely sensitive polling locations.
After Mubarak Zeb Khan abandoned the seat, which he also won in the NA-8 by-election on April 21, the seat became available.