Smoking and Teen Pregnancy examines the risk and protective factors associated with smoking behavior among a cohort of 2,009 pregnant and parenting teens, part of a national multi-site Parenting Adolescent Initiative study. Data were collected at 4 points over 18 months. The results of this study demonstrated that smoking rates were higher than anticipated among this population. Almost 40% of the teens reported either Experimental (Occasional) Smoking (15.5%) or regular Smoking (24.1%) over 18- months. Hispanic and African-American and Other teens were more likely to be Non-Smokers or Experimenters, whereas over half of the White teens were Smokers. The study suggests that race/ethnicity is the most significant predictor of smoking amongst pregnant and parenting adolescents and that Experimental Smokers are at significant risk of increasing their smoking behavior over time. From an intervention perspective, smoking behavior needs to be identified early in pregnancy and, if indicated, culturally based cessation programs need to be initiated soon thereafter and continued throughout the course of the pregnancy.