China has prohibited an extensive list of solid waste from abroad since 2017. While China seeks to move away from being the world's dumping ground, cleaning up its own backyard is proving to be a great challenge. China's Yangtze River economic zone, which covers 11 provinces and accounts for 40% of the country's Gross Domestic Product, has been found to be alarmingly polluted: 74 million metric tons of solid wastes, including industrial solid waste, construction debris, municipal solid waste, and hazardous waste, have been disposed of by dumping. In this study, the statistics and spatial patterns of waste dumping were determined and mapped, and then the subsequent environmental impacts on the local and downstream marine ecosystem were evaluated. The results indicated the largest dumped-waste volume was found in Sichuan province (industrial solid waste) and Hubei province (solid waste mixture). The potential environmental impacts aroused by waste dumping in Hubei, Jiangxi and Sichuan provinces were serious, while the impacts in Yunnan and Zhejiang were slight. It is imperative for the Yangtze River Economic Zone to develop stringent measures for curbing the dumping of solid waste, assessing the implications from existing dumping activities, and enhancing the capacity for responsible waste management.