MK Tamar Zandberg is the new leader of Meretz after she won the first ever leadership primary held in the left-wing party on Thursday.
Zandberg will replace Zehava Gal-On, who dropped out of the race.
Former Peace Now secretary-general Avi Buskila finished second.
The turnout was only 53.6% among some 32,000 eligible voters.
Zandberg promised in campaign stops throughout the day that the party would win 10 seats in the next election.