The aim of the current research is to propose a comprehensive model for value added tax (VAT) audit quality given the environmental characteristics and the conditions governing the country. Accordingly, considering the exploratory approach of the research and using qualitative approach, grounded theory method was used. To this purpose,in the first half of 1398 by asking about the opinions of 26 cases of experts with VAT audit expertise, who had executive experience in this area, through deep interviews, factors affecting VAT audit quality were investigated. Finally, the "integrated model of VAT audit quality in Iran", including causal conditions, interfering factors and the ground, as well as the strategies to achieve VAT audit quality and its consequences was presented. In this research VAT audit quality was investigated using system approach. This perspective has considered the quality of all components of the ruling system in Iran's VAT system. Research data were analyzed, and the main categories and sub-categories(concepts) were extracted. Using system approach that embraces two macro parts, including VAT audit service providers at three micro-levels (work level, tax dispute resolution level, and organizational level) and (VAT taxpayers), the model of VAT audit quality in Iran was designed and the categories emerged in its framework were proposed. Given the lack of comprehensive research in Iran in this regard, the designed multidimensional model is the result of various experts' opinions at the above mentioned levels that presents a comprehensive broad perspective toward tax audit quality in VAT system in Iran.