In recent years, there has been an increase in the adoption of lean manufacturing principles, as well as tools, in multiple industrial sectors. In fact, this management philosophy, which is already well-established, has been applied successfully in other various contexts than just production. However, companies are under pressure to manage their activities, considering their effects in social and environmental terms. In this sense, this study aims to characterize the acceptance of lean by Portuguese companies, as well as the results obtained both in terms of Environmental, Social, and Governance (ESG), as well as in terms of organizational competitiveness (COM) by companies with lean implemented. To this end, a questionnaire was distributed to 3957 companies operating in Portugal, having obtained a total of 373 responses, of which 201 were validated, i.e., a rate of 53.89% valid responses. The results of this study show that companies with lean adopted, also adhere to green management practices (GMP), managing to improve their performance relative to each one of the dimensions of the triple bottom line (TBL), i.e., their ESG outcomes, as well as their COM.