Protected areas can be conceptualized as complex adaptive systems, with feedbacks between social and ecological processes inside and outside their boundaries. Understanding and managing these feedbacks requires as much information and knowledge as possible. Protected area managers on their own are seldom able to collect and process the full array of information required to adaptively manage protected areas, especially in the context of the broader social-ecological landscape. In that sense informal, local and traditional knowledge can be valuable in providing supplemental or even core information required to make complex management decisions. Involvement of local knowledge holders may also assist in building bridges between protected area managers and local stakeholders, and ignoring local knowledge often leads to conflict with subsequent demands on precious human and financial resources. In this presentation we provide a conceptual framework for the role of knowledge, learning and co-innovation in adaptive co-management. We provide examples of informal, local and traditional knowledge and its relevance for biodiversity conservation and protected area management, and of the lost opportunities and conflicts that come to the fore when such knowledge is ignored. We also discuss some of the pitfalls and share ideas of processes and methods that may promote the better use of informal, local and traditional knowledge in adaptive co-management of protected areas.