<jats:title>Abstract</jats:title><jats:p> <jats:list list-type="bullet"> <jats:list-item> <jats:p>In the wake of increasing evidence that youth exposure to alcohol marketing is a risk factor in underage drinking, public health researchers are trying a variety of methods to measure that exposure. Based on lessons learned from more than 20 reports on exposure produced by the Center on Alcohol Marketing and Youth, best practices in data sources, definitions of terms and specific measurement issues such as census versus sampling, identifying the at‐risk population and performing basic calculations of gross rating points (GRPs) and GRP ratios are reviewed, using examples from work of the Center and other public health researchers. Specific recommendations for best practices in calculating and reporting exposure metrics are provided, including how to measure and report trends, differentiating between audit and planning perspectives and the importance of measuring exposure at both the category and the brand level. These recommendations are relevant not only to the monitoring of youth exposure to alcohol marketing, but also exposure to marketing for other potentially harmful products such as foods of low nutritional value, tobacco and pharmaceutical drugs.</jats:p> </jats:list-item> </jats:list> Copyright © 2009 John Wiley &amp; Sons, Ltd.</jats:p>