The study examines the management of Legionella in the Swedish merchant fleet by mapping existing methods and proposing measures. Through a literature review and interviews with shipping company employees and industry experts, three research questions are analyzed: What are the most common preventive measures on board, common sanitation methods and how can these be made more efficient when it comes to eliminate Legionella. The results point to common methods such as UV irradiation and hot water flushing. The discussion highlights the reliability of the method and the industry's need for increased knowledge and clearer guidelines. The conclusions emphasize the need for measures such as Legionella filters, regular testing of fresh water, and long-term solutions focusing on the source of the problem, such as risk assessments. Education, awareness, and preventive measures are crucial for combating this hidden and costly problem in modern shipping.