Commissions of Inquiry (COIs) are a regular occurrence in Hong Kong. By their very nature, they attract much public and media interest. COIs are governed by the Commissions of Inquiries Ordinance (Cap.86). Only the Chief Executive in Council has the power to set up a COI. This power will be exercised when a matter of “public importance” merits investigation. The last three COIs, upon which the text primarily draws, have been (a) the Lamma Ferry collision; (b) Excess lead in the water at public housing developments; and (c) the Hung Hom Station Extension project. This is the first text that "tells you all you want to know" about COIs in Hong Kong. It is a practical guide drawing on the experience and expertise of the Authors who served as counsel to recent COIs (a) Excess lead in the water at public housing developments and (b) the Hung Hom Station Extension project.