The purpose of this chapter was to present a balance of the state of FILAC's diplomatic activities since COP 15 to analyze them in the light of a novel concept, traditional knowledge diplomacy (TKD). A case study is designed that seeks to test the hypothesis that TKD has been used by FILAC as a key asset to integrate Indigenous Peoples' perspectives and voices in the implementation of FILAC's diplomatic practices. Semi-structured interviews and a documentary review of news items were used. The findings were analyzed in three different ways: (a) traditional knowledge (TK) in diplomacy, (b) TK for diplomacy, and (c) diplomacy for TK. The findings were also discussed in light of the characteristics of a TKD. The FILAC case study provided a common understanding of TKD for international relations and an example of how it can be methodologically investigated. In this way new avenues of research, complementary to scientific diplomacy (SD), were opened.