There has been a growing interest in remanufacturing during the past decade, since it offers many advantages to our economy. However, the qualification and quantification of the benefits of remanufacturing compared to original manufacturing remain confusing to us due to the difficulties of data collection in complex production processes and the lack of accurate and convinced evaluation method. Life cycle assessment (LCA) is a “cradle to grave” approach for assessing industrial products and systems, which enables to estimate the cumulative environmental impacts resulting from all stages in a product life cycle. In this book, taking a diesel engine as a case study, a comprehensive LCA is conducted for remanufactured diesel engines, aiming to identify the negative impact on the environment during the whole life cycle and to analyze the potential that remanufacturing had in terms of energy savings and environment protections. In order to demonstrate the environmental benefit of remanufacturing, the environmental impacts achieved in the study are compared with a newly manufactured counterpart. The results show that remanufacturing of a diesel engine has lesser contribution to all the environmental impact categories when compared to its original manufacturing; the greatest benefit is EP which is reduced by 79 %, followed by GWP, POCP, and AP which can be reduced by 67 %, 32 %, and 32 %, respectively.