A 54-year-old man presented with fever, vomiting, jaundice and conjunctival injection. These clinical signs, together with the presence of mild inflammation, hepatitis and severe acute kidney injury, lead to the suspicion of leptospirosis. Infection was serologically confirmed and treatment with ceftriaxone and intermittent haemodialysis was followed by rapid clinical and biochemical recovery. Worldwide, leptospirosis is an emerging pathogen as a result of overpopulation and flooding, but due to increasing tourism also in other regions. In Belgium, clinicians must be aware of endemic as well as imported cases of leptospirosis and differentiate them from hantavirus infections. Leptospirosis is a zoonosis that is transmitted through the urine of chronically colonized animals, mainly rats. Infection can be asymptomatic, present as a mild inflammatory syndrome or cause a severe icterohaemorrhagic disease with multiple organ failure and a high mortality rate. Initial serological diagnosis requires confirmation with a microscopic agglutination assay in a reference laboratory. Treatment is mainly supportive. Antibiotics are often used although mild acute infection often is self-limiting and there is uncertainty about the influence of antibiotic therapy on the duration of fever or mortality. In general, patients fully recover with no remaining organ damage.