Abstract Background Sophisticated, persuasive and extensive product marketing is a key driver of unhealthy commodity (UHC) consumption. This study aims to identify the nature and extent of children’s exposure to UHC marketing. Methods The study is a secondary analysis of Kids’Cam, a cross-sectional study in which 168 New Zealand 12-year-old children wore body cameras that automatically captured images of their environment every 7 seconds over four days. Images were analysed for exposure to UHC, Healthy and ‘Other’ marketing. Results Children were exposed to UHC marketing on average 76.2 times/day, nearly 2.5 times their daily exposure to ‘Healthy’ marketing. Exposure included: unhealthy food marketing (68.4/day), alcohol (5.7/day), gambling (2.1/day) and tobacco marketing (0.1/day). These exposure rates align with the level of statutory regulation each UHC faces in NZ. Food outlets were the most common setting for UHC marketing exposures, while product packaging was the most common medium. Coca-Cola (6.3/day) was the most common UHC exposure, followed by Cadbury, Tip Top, Bluebird and Powerade. Over half of children’s unhealthy food (54.9%) and alcohol (51.9%) marketing exposures were attributed to multinational corporations. In contrast, statutory bodies are responsible for almost all (97.4%) of children’s gambling marketing exposure. Conclusions Children currently grow up in an environment in which they are constantly persuaded to consume products that directly harm their health - an environment in which the profits of corporations are favoured over public health. Statutory regulation of UHC marketing is urgently needed to protect children from harm. Key messages • Children were exposed to unhealthy commodity marketing on average 76.2 times/day, nearly 2.5 times their daily exposure to ‘healthy’ marketing. • Statutory regulation of unhealthy commodity marketing is urgently needed to protect children from harm.