Polyhalogenated carbazoles (PHCZs), an emerging class of halogenated organic pollutants, have been widely detected in various environmental media, including sediments, soil, air, and organisms. The East China Sea (ECS) is a vital region for marine and fishery resource development in China, yet research on the pollution levels and sources of PHCZs in its sediments remains limited. This study reports the occurrence of seven PHCZs in the surface sediments of the ECS, with detection rates exceeding 90%. The concentrations of Σ