The past few decades have witnessed relentless economic growth and increased human welfare due to extreme competition from companies globally and increasingly demanding users. This has led to extreme exploitation of natural resources, with dramatic consequences for the environment. In the coming years, the transition to more environmentally sustainable models must be central for companies. One possible solution for manufacturing companies, is to address environmental sustainability needs by developing a Lean approach. In recent years, the Lean approach to environmental sustainability has gained increasing attention, both from academia and companies. Nevertheless, there are still several aspects to investigate on the influence of the lean approach on environmental sustainability. This paper through the analysis of a case study of an Italian manufacturing company shows how the use of the lean approach, through the A3 problem solving framework, enabled the company to improve its sustainability performance. Specifically, the company was able to identify and eliminate non-value- added handling in its warehouse, decreasing forklift kilometrage and consequently limiting fuel consumption and CO2 release.