The research focuses on gathering detailed theoretical and empirical data on the operational activities of international non-governmental organizations in Bulgaria, their functions, sources of funding, governance practices and important problems that these organizations face in their work. The research is exploratory in nature and uses a qualitative design and the deductive research approach in examining the operation and management issues that INGOs face in Bulgaria. The findings in the project summarize the results from the gathered empirical data after developing data analyses of the performed ten interviews with INGOs in Bulgaria and the author's personal observations on the respondents' corporate websites. By comparing the results of the interviewees' answers some basic conclusions were made by using certain criteria. The general conclusions drawn are on the basis of the theoretical framework presented in the first three chapters and the summarized findings after analyzing the data set in the empirical part. General patterns, characteristics and differences were discovered among the INGOs in Bulgaria that could be the basis for further more extended and detailed research.