INTRODUCTION: Increasing excise tax on tobacco is one of the most powerful and cost-effective smoking interventions. Despite this evidence, there has been no substantial tax increase in New Zealand between 2000 and 2010. In April 2010 a 10% tax increase on factory-made cigarettes and a 24% tax increase on loose leaf tobacco was implemented. AIM: To evaluate the effect of cost as a motivating reason for smokers to make a quit attempt before and after the 2010 tobacco tax increase. METHODS: A regression analysis of a cross-sectional study was conducted. Data were collected from August to October 2009 and compared with data collected in July 2010. RESULTS: In 2009, 25.5% of smokers cited cost as a reason for trying to quit smoking compared with 55.6% in 2010. The adjusted odds of making a quit attempt with cost as a reason were 3.6 (95% CI 2.3–5.6, P=<0.001). Furthermore, smokers were more likely to make a quit attempt in 2010 than in 2009. Thirty percent of smokers made at least one quit attempt in 2009 and 39% made a quit attempt in 2010 (adjusted odds ratio 1.5, 95% CI 0.95–2.3, P=<0.1) DISCUSSION: The recent tax increase on tobacco in New Zealand has resulted in more smokers making an attempt to quit smoking and more smokers identifying cost as a motive for quitting. KEYWORDS: Smoking; smoking cessation; tobacco; taxes; New Zealand