In this prospective longitudinal study, the authors investigated the association between lifetime tobacco use and subsequent health problems by age 30. The authors interviewed a community group of 749 participants from upstate New York at mean ages of 14, 16, 22, and 27 years. Daily tobacco use during any of the time periods, as well as the number of periods of daily tobacco use, were significantly associated with increased risk for respiratory ailments, neurobehavioral and cognitive problems, and general malaise. The results suggested that daily tobacco use, either during childhood, adolescence, the early 20s, or a combination of those times, predicted health problems by age 30. Effective smoking prevention programs that begin in childhood are imperative to prevent the occurrence of later health problems. (Contains 3 tables.)