Alcohol and tobacco usage patterns were assessed in 1,811 children and young adults, 12-24 years of age. The prevalence of cigarette smoking and alcohol consumption increased with age in all race and sex groups. Smokeless tobacco use (chewing tobacco and snuff) was primarily seen in white males with the highest prevalence rates in 12-15 year olds. Among white males who reported smokeless tobacco usage, 44% of the 12-17 year olds and 80% of the 18-24 year olds reported concurrent alcohol use. There was a significant interaction between alcohol consumption and cigarette smoking in all four race-sex groups (p less than 0.001). Given the potential synergistic relationship between ethanol and tobacco products on oral and upper gastrointestinal tract cancer, as well as between smoking and cardiovascular disease, the long term effects from these behaviors could be troublesome. Since healthy lifestyles are established in youth, early intervention on alcohol and tobacco use is needed to prevent the future morbidity and mortality from cancer and cardiovascular disease.