This study examines the impact of the independent board, independent audit committee and institutional ownership on voluntary disclosure (by placing company size as a moderating variable) in Indonesia banking companies. Data collected from the annual report of banking companies listed on the Indonesia Stock Exchange throughout the year of study. Hypotheses developed to be tested with a variance based approach and the results were interpreted. The result has shown that the increase of independent board members and independent audit committee members tend to decrease the level of voluntary disclosure (although the impact is not significant). Independent board and independent audit committee performed this to reduce cost due to a high disclosure and to avoid the threat of high competition in banking companies. The other result has shown that institutional investors are considered more professional and powerful in supervising management to disclose more information to the public. The final section of the study's findings indicated that firm size cannot be as a moderating variable on the impact of the independent board, independent audit committee and institutional ownership toward voluntary disclosure.