The objective of this study was to examine the effectiveness of a longitudinal community intervention on the reduction of tobacco sales to minors and subsequent effects on tobacco consumption by youths. The study was conducted in Monterey County, CA. Four rural communities were randomized into treatment and comparison arms of the study and middle and high school students in each of these communities completed surveys assessing knowledge, attitude, and behavior. The main outcome measures were retail tobacco sales to minors as measured through store visits (tobacco purchase surveys) and self-reported consumption of tobacco. Over a three-year period, a diverse array of community interventions were implemented in the intervention communities. These included community education, merchant education, and voluntary policy change. In the treatment communities, the proportion of stores selling tobacco to minors dropped from 75% at baseline to 0% at the final post-test. In the comparison communities, the proportions were 64% and 39%, respectively. Although the availability of tobacco through commercial outlets was reduced substantially in intervention communities, youths reported still being able to obtain tobacco from other sources. Predicted treatment effects on reported use of tobacco among youths were observed cross-sectionally and longitudinally for younger students (7th graders). The intervention did not impact tobacco use among older students (9th and 11th graders) although the trends were in the predicted direction for 9th graders. A significant intervention effect was found for sex--females in the intervention communities were less likely to use tobacco post-intervention than females in the comparison communities. Tobacco sales to minors can be reduced through a broad-based intervention. To prevent or reduce tobacco use by youths, however, multiple supply-and demand-focused strategies are needed.