Congress candidate Pratibha Singh on Sunday won the Mandi Lok Sabha by-election with a margin of over 1.36 lakh votes.
According to television reports, Singh defeated her nearest rival Jai Ram Thakur, a Bharatiya Janata Party (BJP) legislator.
The by-poll was necessitated after Virbhadra Singh was elected to the Himachal Pradesh Assembly in December last year.
Polling was held on June 23.