Opinion polls from prior to the election had suggested the Saenuri Party would win the election outright, and were confounded by Saenuri underperformance in constituencies and the comparative success of the Democratic and People's parties.
The KBS exit poll on April 13 showed the Saenuri Party winning a plurality with between 121 and 143 seats, and the Democratic Party taking 101–123; other exit polls projected similar results.
South Korean law had prohibited the publication of opinion polls in the week before the elections, beginning on April 7.

General notes
Gallup Korea provides poll results only to the nearest whole number.
Opinion polls from prior to the election had suggested the Saenuri Party would win the election outright, and were confounded by Saenuri underperformance in constituencies and the comparative success of the Democratic and People's parties. The KBS exit poll on April 13 showed the Saenuri Party winning a plurality with between 121 and 143 seats, and the Democratic Party taking 101–123; other exit polls projected similar results. South Korean law had prohibited the publication of opinion polls in the week before the elections, beginning on April 7.
General notes
Gallup Korea provides poll results only to the nearest whole number.
2016 South Korean legislative election