Q fever is a worldwide zoonotic infection caused by the obligate intracellular bacterium Coxiella burnetii that can course with acute or chronic disease. This series describes 7 cases of acute Q fever admitted in a Portuguese University Hospital between 2014 and 2015. All cases presented with hepatitis and had epidemiological history. Diagnosis was done by PCR on majority (5) and by serology and PCR in only 2. Serological tests can be negative in the initial period of the disease. Molecular biology methods by polymerase chain-reaction are extremely important in acute disease, allowing timely diagnosis and treatment.