The Kerdau seat fell vacant following the death of its state assemblyman Datuk Zaharuddin Abu Kassim of United Malays National Organisation, part of the Barisan Nasional coalition from a heart attack at his home.
[1][2] Previously Zaharuddin Abu Kassim won the Kerdau seat with a 1,615 vote majority, beating PAS' Hassanuddin Salim at the 2008 Malaysian general elections.
[3] The state assembly seat has 8,721 voters registered compromising of 88.36% Malays, 3.6% Chinese, 3.4% Indians and 2.98% other races.
[4] For the by-election PAS picked as its candidate, Hassanuddin Salim while Barisan Nasional picked Syed Ibrahim Syed Ahmad.
[5] Syed Ibrahim Syed Ahmad, the Barisan candidate won by polling 5,060 votes against the 2,336 garnered by Hassanuddin Salim of PAS.