Abstract Purpose: The primary goal of this thesis is to provide a deeper understanding of how big data affect professional judgment, audit efficiency, and perceived audit quality. It also aims to explore the effect of Big Data Analytics (BDA) on the skills and competence required by auditors to perform an audit in a big data environment. Theoretical perspectives: Theoretical concepts base on previous research and publications by practitioners and regulators on BDA, professional judgment, audit efficiency, and audit quality. Literature was used to derive the research gap and research questions. Methodology: A qualitative method base exploratory approach. A literature review was conducted to uncover areas of interest that require more research. The effect of data analytics on the audit was identified as a potential area for research; a focus on audit quality was chosen, including key factors that contribute to overall audit quality. The research is based on semi-structured interviews with auditors from big four audit firms in Sweden. Empirical foundation: Empirical evidence was generated through an interview with seven auditors at different levels of the professional hierarchy. Empirical data was analyzed using a thematic data analysis approach. Conclusions: The findings of this research show that using BDA in the audit methodology affect the required skills and competence by auditors to carry out audit engagement activities. More IT related skills and knowledge gaining prominent in the audit field. Implementing data analytics will not be efficient in the early stage but will save time as auditors become more familiar with the tools. Data analytics improve audit quality. Auditors use analytics to gain more insight into the client’s business and communicate such insights to clients. It was found that data analytics generate fact-based audit evidence. The visualization ability enables auditors to visualize and analyze audit evidence to guide their professional judgment and decision making. Key words: Big data, Data analytics, Auditors skills and competence, Audit process, Audit efficiency, Audit quality and Professional judgment.