Climate change is arguably the most important issue facing humanity today. To help address this issue, the current research aimed to better understand the psychological and demographic antecedents that predict pro- environmental behaviour. The 2012 NZGSS, a survey of 8,462 New Zealand men and women aged 15 years and over, was used to assess the predictive power of several variables on people’s recycling, energy conservation and water conservation behaviours. Results showed that women, older people, higher income people and higher qualification people showed the highest levels of pro-environmental behaviour, while psychological variables had varying effects. The current research adds to the collective knowledge around pro-environmental behaviour, and a theory is proposed to help explain demographic differences.