Accounting conservatism and managerial ownership is applied as a means to minimise agency problems. However, different type of ownership will have different level of conflict. Family ownership is deemed to be more affected by agency problem type II. Using the data of Kompas 100 listed firms in Indonesia, this study aims to comprehend the effect of a family ownership and its level of accounting conservatism. The study also analyses the correlation between managerial ownership toward the level of accounting conservatism. Findings show that family business significantly affects the level of accounting conservatism. In contrast, this study cannot find any effect on managerial ownership on the degree of accounting conservatism.