Background E-cigarettes are growing in popularity. Dual use of e-cigarettes and cigarettes is an increasingly common practice, but little is known about patterns of dual use in parents. We sought to describe smoking-related behaviors among dual-users. Methods Parent exit surveys were conducted following their child's visit in 5 control pediatric practices in 5 states participating in the Clinical Effort Against Secondhand Smoke Exposure trial. We examined factors associated with dual use of e-cigarettes and cigarettes versus cigarette-only smokers, assessed by self-report. Results Of 1382 smokers or recent quitters screened after their child's visit between April and October 2017, 943 (68%) completed the survey. Of these, 727 parents reported current use of cigarettes; of those, 81 (11.1%) also reported e-cigarette use, meeting the definition of dual use. Compared with cigarette-only smokers, dual users were more likely to have a child younger than 1 year old, planned to quit in the next 6 months, and had tried to quit in the past (had a quit attempt in the past 3 months, called the quitline, or used medicine to quit in the past 2 years; P Conclusions Parents who use both e-cigarettes and cigarettes may have greater rates of contemplating smoking cessation than parents who only smoke cigarettes. These parents may be using e-cigarettes for harm reduction or as a step toward cessation. Identification of these parents may provide an opportunity to deliver effective treatment, including nicotine-replacement therapies that do not expose infants and children to e-cigarette aerosol.