Background: The Product Safety Programme (PSP) of Health Canada is responsible for preventing product-related injuries. If PSP decides a product is dangerous, it can publicize its dangers, prohibit, or control its distribution; but for child products, the preferred option is to publicize its concerns. In the past, this included sending posters to paediatricians' offices and, more recently, placing alerts on the PSP website. This study examines the effectiveness of this process. Methods: 15 Montreal paediatricians participated in a modified crossover randomized trial. During a randomly chosen intervention week, two product-related notices were posted in the paediatricians' waiting area. In the following or preceding week, these notices did not appear. Parents were interviewed by telephone to determine if they saw the posters and acted on the information received. Results: We interviewed 808 parents (86%) of the 940 who agreed to participate. Of these, only 16% of the intervention and less than 1% of the control group reported seeing the posters. There were no differences in reported changes in behaviours related to the notices. These findings are unchanged after taking account of socioeconomic status. No parents cited the posters, websites, or paediatricians as their main source of information about dangerous products. Conclusion: Product safety notices, whether sent to paediatricians' practices or posted on a website, cannot be relied upon to reach parents of preschool age children. Other approaches require consideration, such as increasing the power of PSP to regulate product safety. Mesh terms: Health promotion; public health; safety management; promotion of health; knowledge/attitudes/practices La traduction du résumé se trouve à la fin de l'article.