While much is known about the impact of public policy on current cigarette smoking among adults, very little is known about the determinants of some-day smoking. This paper investigates the impact of cigarette prices, clean indoor air laws, and other socioeconomic factors on adult cigarette demand. Special emphasis is placed on examining the determinants of some-day smoking among adults. The estimates from this study clearly indicate that increasing the price of cigarettes, will decrease the number of people who currently smoke, will decrease the number of every-day smokers, and will decrease the number of cigarettes smoked on average among some-day smokers. Finally, clean indoor air laws are found to have a limited impact on current and some-day smoking.