Objectives: To explore how and why tobacco smokers and recent quitters in NSW use e-cigarettes, as well as common places of purchase. Design: The Cancer Institute Tobacco Tracking Survey is a serial cross-sectional telephone survey, with 40 interviews in NSW each week. Participants: 2966 tobacco smokers and recent quitters (in the past 12 months) interviewed January 2014 e June 2015. Measures: Current e-cigarette use; reasons for using; places of purchase. Results: 9% of the sample reported currently using e-cigarettes; the rate was highest among 18e29-year-old people (16%). Infrequent use (less than weekly; 57%) was more common than frequent use (at least weekly; 43%). Frequent use was more likely among older adults (55 years and older v 18e29 years: adjusted odds ratio [aOR], 4.43; P=0.002) and less likely among current tobacco smokers (v recent quitters: aOR, 0.38, P=0.020). The most common reasons for using e-cigarettes by those over 30 years of age was “to help me quit” (42%) and to “cut down” smoking (35%); for younger adults it was “because they are not as bad for your health as cigarettes” (25%). Common places of purchase were the internet (29%) and tobacconists (27%). Conclusions: Although use of e-cigarettes by tobacco smokers in NSW remains low, some are using e-cigarettes in attempts to reduce tobacco-related harm. Physicians and public health campaigners should inform smokers about the risks associated with dual e-cigarette and tobacco use, advise interested quitters that e-cigarettes are currently unregulated as cessation aids, and continue to provide evidence-based recommendations and cessation services to smokers wanting to quit.