Brownfield sites in Hong Kong lack an official definition. This study aims to provide a comprehensive report on brownfield sites through historical analyses, land investigations, case studies, and international policy reviews. An investigation in 2015 found over 1,192 hectares of brownfield sites, consisting mainly of container yards, open parking areas, and storage/waste areas in northern New Territories. A case study on a shelved public housing development project in Wang Chau highlighted issues of inefficient land use and suspected illegal occupation of government land. The report recommends establishing a clear brownfield definition, integrated territory-wide brownfield policies, and a public brownfield land database to improve land management.