This paper examines the extent to which parent and grandparent smoking influences adolescent smoking and its quantitative implications for tobacco control. It extends similar prior studies by investigating the effects on the probability of becoming a smoker and on the number of cigarettes smoked. Count regressions were used to assess the intergenerational transmission of smoking across three cohabitant generations, simultaneously, using data from the 2010 survey "Encuesta Estatal Sobre Uso De Drogas en Estudiantes de Enseñanzas Secundarias". This survey, of 32,234 students, constitutes a representative sample of Spanish students between 14 and 18 years of age. Living with a mother who smokes, a father who smokes, or a grandparent who smokes reduces the odds of being a non-smoker by 36.1% (OR 0.639), 26.1% (OR 0.739) and 20.3% (OR 0.797), respectively. Parental smoking increases cigarette consumption levels among adolescents. Having a cohabitant mother who smokes increases the number of cigarettes smoked by children by around 18.7% (IRR 1.187), while having a cohabitant father who smokes increases the number by around 12.1% (IRR 1.121). Estimates support the hypothesis that visibility of smoking among parents and grandparents is a strong predictor of smoking among adolescents. Accordingly, quitting smoking by parents and grandparents before children become adolescents appears to be a powerful means to both reduce smoking rates among adolescents and the number of cigarettes smoked by smokers; such decisions appear to exert a stronger influence on the prevalence of smoking and consumption levels than exposure to smoking prevention campaigns at school.