This study examines the effect of unrelated diversification strategy to real earnings management. This study also examines the impact of the BOC oversight and family ownership on the effects of unrelated diversification strategies to real earnings management. Real earnings management is measured by abnormal cost production approach and abnormal discretionary cost. Unrelated diversification strategy level is measured by entropy measure. This study used 766 observations of listed companies on the Indonesia Stock Exchange during the period 2013-2015. The result of this study indicates unrelated diversification strategy positively affect the company's real earnings management. The higher level of unrelated diversification made by the company will make the higher real earnings management. However, Board of Commissioners oversight and family ownership has no significant effect on positive effect of unrelated diversification strategy to real earnings management. The result of this study indicates that the company's diversification strategy can also affect issues in the field of Accounting such as earnings management. In addition, the results of this study can also be used by DSAK as a regulator related to financial reporting on companies diversify unrelated to prevent the occurrence of earnings management.