Diplomacy Investment has been the superlative source of extrinsic finance for developing country. Economic diplomacy is concerned with conducting international business. The general objective of this study was to assess the diplomacy and investment through Ministry of Foreign Affairs and International Cooperation. Specifically, the study focused on to examine the effect of the public diplomacy on investment, to establish the effect of economic diplomacy on investment, and to determine the effect of science diplomacy on investment through Ministry of Foreign Affairs and International Cooperation. Qualitative and quantitative methods were used in the design of the descriptive study. Information gathered by use of questionnaire. Eighty-one respondents working for the Foreign Affairs and International Cooperation Ministry were polled. Since the research used a census-based approach, the whole population served as the sample. Statistical Package for Social Sciences version 26.0 was used to conduct descriptive statistics on the given data. We also utilized inferential statistics to demonstrate the interdependence of the variables. The outcomes are visually represented by tables with frequency distributions, means, and standard deviations. According to research commissioned by the MINAFFET, there is a statistically significant relationship between public diplomacy (p=0.000 less than 0.05), economic diplomacy (p=0.00 less than 0.05), and science diplomacy (p=0.001 less than 0.05) and investment. An R value of.921, a R square value of 0.848, and an adjusted R square value of 0.842 were discovered. The Ministry of Foreign Affairs and International Cooperation channels 84.80% of its investment via science diplomacy, economic diplomacy, and public diplomacy. The significant level from the analysis of variance was 0.000 which is less than 0.05, and the corresponding result was F=128.449. This means that the Science Diplomacy, Economic Diplomacy, and Public Diplomacy programs run by the MINAFFET have an influence on investment, as hypothesized by the study's author. The MINAFFET should prioritize and