The by-elections were held on 10 February for seven constituencies, with the nomination day held on 31 January. With 80,075 registered voters, the 1979 by-elections remain the largest by-election to have ever taken place in post-independence Singapore.
Continuing the trend of People's Action Party's renewal just as they did in the 1970 by-elections, six seats, including Communications minister Yong Nyuk Lin, were vacated on 12 January to make room for six new MPs. A seventh seat in Anson was earlier vacated a year prior following the death of Perumal Govindaswamy. As such, the seven seats at stake is widely regarded as the biggest-ever by-election in Singapore's history, and it had the most seats changed since the Barisan Sosialis' mass exodus back in the inaugural Parliament back in 1966.
The United People's Front criticized Barisan Sosialis for abstaining the by-elections citing an uphill contest against opposition stalwarts. In the end, only Geylang West (which one United Front (now Democratic Progressive Party) candidate was later disqualified) and Nee Soon were uncontested. As of 2024, this by-election was the most recent by-election in Singapore with walkovers.
The by-election saw the return of Devan Nair into Singapore politics since 1963, as well as future minister Tony Tan; both of these candidates would go on to become Presidents of Singapore.