This study aims to determine the effect of task complexity on the performance of internal auditors with professionalism and work motivation as a moderating variable on representatives of the financial supervision and development of Yogyakarta special area. The population in this study was the auditor representative of the Yogyakarta Special Region and Financial Supervision Agency. The sample in this study was determined using purposive sampling method as many as 34 who were auditors working at BPKB DIY. The type of data used is primary data through questionnaires. Data analysis methods used are data quality test, classic assumption test, moderation regression and hypothesis testing. The results showed that task complexity had a significant positive effect on auditor performance. The moderation regression concluded that professionalism is not able to moderate the relationship of task complexity to auditor performance and work motivation to moderate the relationship of task complexity to auditor performance is said to be unsuccessful.