Purpose - Despite significant amounts of environmental management tools that are available for companies to use, no model guides them toward environmental excellence. As a consequence, the purpose of this paper is to develop an environmental management maturity (EMM) model that helps companies that are on the path toward environmental excellence. Design/methodology/approach - An iterative process was used to develop this model, starting with some semi-structured interviews with 19 companies within the Basque Country and two workshops with environmental experts. Following these steps, the initial version of the model was developed. Data from subsequent surveys carried out in Spanish and Italian companies, and a survey and semi-structured interviews in companies in the UK were incorporated into the model, yielding the final, more robust version of the EMM model. Findings - The EMM model proposes six maturity stages: legal requirements, responsibility assignment and training, systematization, ECO2, eco-innovative products and services, and leading green company. Each stage details a series of elements: description, agents involved, policies, tools, indicators, structure, and behavior over time graphs. This research confirms that a company's environmental management evolves through several distinctive stages, regardless of the industrial sector. Originality/value - The proposed model concludes that the defined maturity stages provide valuable guidance for industrial firms as it helps them identify their maturity stage as well as the steps they should follow to move to the next stage.