The riding was a Liberal stronghold both federally and provincially for over half a century; however, a growing religious and agricultural population has turned this district into one of the most conservative areas of Ontario.
Most of the riding is fairly Conservative. In the 2006 election, Deep River was the only significant community which voted Liberal. Pikwakanagan, a First Nations reserve, also voted Liberal, and the Township of Wylie had a tie vote. A small handful of polls in Pembroke voted Liberal, but most of the city voted Conservative.
It consisted of the County of Renfrew, excluding the Townships of Bagot and Blythfield and McNab, and the part of the Territorial District of Nipissing including and lying easterly of the Townships of Mattawan, Papineau, Cameron, Deacon, Anglin, Dickson, Preston, Airy and Sabine.
The electoral district was abolished in 1987 when it was redistributed into Renfrew riding. In 1989, Renfrew riding was renamed "Renfrew—Nipissing—Pembroke".
The new riding consisted of the County of Renfrew, and the part of the Territorial District of Nipissing lying east of and including the townships of Deacon and Lister, and east of but excluding the townships of Freswick, Bower and Sproule, and east of and including the townships of Airy and Sabine.
In 1996, the Nipissing part was redefined as being the part of the district lying east of and including the townships of Deacon and Lister, east of and excluding the townships of Freswick, Bower, Sproule and Nightingale, and east of and including the Township of Sabine.
In 2003, it was given its current boundaries as described above.