Geographical accessibility is fundamental when planning rescue services. At present there are several programs for computing the accessibility of stationary rescue units. This study suggests a method for evaluating geographic accessibility in scenarios containing also non-stationary units. The method supports the planning process by matching the risk of an incident occurring with the rescue units’ capabilities and accessibility. The method is implemented in the computer program Rescue Unit Planner. The result of the analysis is presented in thematic maps and graphs as level of coverage, mean response time and concentration. The method and the computer program have been evaluated in two case studies: one urban area in southern Sweden and one rural area in northern Sweden. The case studies show that that this method can be useful in the rescue service planning process.