Karyn Paluzzano Labor Stuart Ayres Liberal A by-election was held for the New South Wales Legislative Assembly seat of Penrith on 19 June 2010.

[1] The by-election was triggered by the resignation of sitting Labor member and former Parliamentary Secretary for Education and Training Karyn Paluzzano, who had lied to an Independent Commission Against Corruption (ICAC) inquiry over her actions, such as signing false staff payslips and rorting her electoral mail allowance.

In addition to the scandal surrounding Paluzzano, Labor was only polling at 39% support, a marked drop from the 2007 election.

While Premier Kristina Keneally had invested considerable time into rehabilitating Labor's image since ousting Nathan Rees in a caucus coup, it was not enough to improve her party's standing in the polls.

The loss of Penrith presaged Labor's massive defeat at the 2011 state election nine months later.