The environmental impacts of rotary kiln incineration, which is widely used in China for treating industrial hazardous waste (IHW), is evaluated in this work through life cycle assessment (LCA). Emissions data of key pollutants, along with energy and material inputs and outputs of rotary kiln incineration, were collected from a commercial-scale operating IHW incineration plant located in Hangzhou city in eastern China, and the corresponding environmental impacts were analyzed based on the LCA model. It is concluded that the IHW incineration process has the greatest impact on human toxicity, followed by global warming. Heavy metals, especially Pb and As, are the main contributors to human toxicity, while CO2 is the main cause of global warming. PCDD/Fs have a relatively small contribution to human toxicity and overall environmental safety. This study has two improvement suggestions based on the assessment results: An energy recovery system and a DeNOx system should be added to the IHW incineration process, since the former would reduce the contribution of IHW incineration to global warming, while the latter would enable incineration plants to minimize the emissions of NOx; Fly ash and bottom ash should be stabilized and further treated to mitigate the problems caused by heavy metals.