Our paper extends channel complementarity theory, which has focused on evidence of complementarity and patterns of channel use, by elucidating the notion of trust complementarity. We examined trust, an information-carrier characteristic and a core construct in health-focused decision-making to understand cancer information seeking, based on data from two nationally representative surveys in Singapore. Trust is found to be differential, relational, and ecological, with implications for individuals’ access to and reliance on doctors, family/friends, newspapers/magazines, radio, TV, and the Internet for cancer prevention information. In an ideal trust complementarity environment, an individual should be able to traverse a range of communication channels seamlessly. Our findings however suggest that although individuals trust different channels complementarily, their trust patterns are limited and fettered. We identified two types of trust ecologies shaped by dual-channel and polymorphic complementarity patterns that suggest that health information seekers are trapped within specific trust ecologies that prevent them from navigating a broader range of communication channels for cancer prevention.