The purpose of this study is to investigate the challenges of tax auditing of legal entities and analyze them using MADM methods. This research is applied in terms of purpose and exploratory mixture in terms of the type of data collection. The study consists of three parts. In the first part, the factors were identified through a qualitative meta-synthesis method using the seven-step method of Sandlowski and Barroso (2007). In the second part, the results were screened and localized using the fuzzy Delphi technique, and in the third part, the cause-and-effect relationships of dimensions and components were investigated through the DEMATEL technique. The research experts consisted of 16 university professors, auditors, and tax managers. The researcher's findings included 7 dimensions, 23 components, and 116 indicators. These results were categorized into seven categories: deviations and perceptions, organizational and structural, cultural and social, interaction and cooperation, laws and regulations, information technology and education, and empowerment. The importance of taxation and the growth and prosperity of the country is not hidden from anyone. However, what is needed to reduce the challenges of tax auditing requires serious determination and all-round unity on the part of all decision-making centers.