This diploma thesis deals with research in global microfinance sector. Currently the paper is focused at techniques of audit used by microfinance investment vehicles to control or to check the transparency or reliability of microfinance institutions. Also, this audit techniques could be used to check achievement of the social goals of microfinance institutions. The analyzed data are from last decade (between 2005 and 2015) provided by microfinance institutions to microfinance web based platform Microfinance Institution Exchange Market. The audit techniques examined in this thesis are the following: due diligence, rating and social performance. This paper insists on objective assessment of all data and information provided freely which relate to audit of microfinance institutions. These data and information are progressively investigated through the whole thesis in two main areas, i.e. quantitative and qualitative. The main objective of this paper is to find the most effective way how to do audit in microfinance or to find out the combination of the available methods.