This report contains the results from the project SEAMLESS, Strategic Environmental Assessment and Management in Local authoritiES in Sweden. The aim of SEAMLESS was to explore conceptual foundations as well as feasibility of establishing better operational and methodological linkages between tools for strategic environmental planning, assessment and management, especially between SEA (according to the EG directive 2001/42/EC and EMS based on the main principles of ISO 14001/EMAS) in local authorities. The rationale for the study was that local authorities are important actors on the environmental arena, which make and implement a large number of decisions directly and indirectly affecting the environment. A multitude of different systems and tools have been developed to support environmental management at local authorities and an integrated use of different tools can have various benefits. The SEAMLESS project has been realized through five main steps. First, a literature review and a survey of international practice were performed. Second, in parallel to the first step, an initial conceptual framework was constructed. The third step in the research process was to carry out case studies in six selected Swedish local authorities in order get a better understanding of how SEA and EMS are dealt with in practice. In the fourth step, the results from the previous steps in the research process were compiled and analyzed in order to develop and conduct a pilot study. Finally in the fifth step, general recommendations for integrated use of strategic planning, assessment and management tools were formulated. Theoretically, local sustainable development strategies could benefit from having influence from some of the main approaches and principles in SEA and EMS methodologies. Achieving this in practice, however, is a challenge that requires a wide systems perspective and a certain degree of maturity in the organization. At the time of SEAMLESS an integrated approach of SEA and EMS was not possible nor asked for by the studied local authorities. The SEAMLESS project‘s core concepts tool technique and tool practice were used for explaining and analyzing the preconditions, possibilities and difficulties in integrating SEA and EMS. Tool technique addresses the more technical aspects of the tools use and integration, neglecting the context in which it is to be used. Applying a tool technique perspective there are several possible linkages between the studied tools that could enhance each tool, e.g. widening the scope of EMS and facilitating follow up of SEA. It is important to understand the context, since it influences the feasibility of tool integration; therefore a tool practice perspective is needed. Furthermore tool integration is another important concept in the SEAMLESS project, where three different stages of integration were identified: formal integration, learning integration and interactive integration. A too strong focus on formal integration (which is closely connected to tool technique) might lead to that potential linkages are not realized. To make such integration possible the focus should be more on learning integration. Interactive integration is hard to achieve and it can be questioned if it is desired. Too much focus on interactive integration might lead to complex resource demanding tool causing ineffectiveness and tool fatigue. The SEAMLESS project resulted in a set of recommendations based on that integration should not be seen as a goal in itself; that attempts of tool integration should focus on bridging the different professional cultures; and that a wide systems perspective is needed.