Leptospirosis is a global widespread zoonosis caused by a Gram-negative bacterium of the genus Leptospira, belonging to the Spirochaetes phylum, favored by unhealthy living conditions and some professional and recreational aquatic activities. Its diagnosis could be very difficult due to the presence of non-specific clinical presentation and biological anomalies common to other infectious diseases. To detect it, the choice of the right diagnostic method is fundamental. We hereby introduce the case of a patient with no classic risk factors for leptospirosis, showing febrile headaches and rapid deterioration of her general conditions with evolution towards septicemia.