In order to improve the exercises that are carried out in future and to ensure that the crisis management system continues to evolve, it is necessary to learn from the experience gained from previous exercises. This report describes the exercise called the National Cyber Security Exercise 2018 (NISÖ 2018), which was conducted on 14–15 February 2018. The report also sets out the experience gained from the planning and execution of the exercise, as well as necessary cross-entity improvements. NISÖ 2018 was planned, executed and evaluated by the NISÖ 2018 project. The exercise consisted of a simulation exercise with role-play at the Swedish Armed Forces Command and Control Regiment in Enköping.