Objectives: The objective of this study was to assess the epidemiology and burden of Q fever (QF) in Spain. Methods: We designed a retrospective descriptive study using the minimum basic data set in patients admitted to hospitals of the National Health System between 1998 and 2015 with a diagnosis of Q fever (ICD-9: 083.0.). Results: We found 4214 hospitalized patients with a mean age (±SD) of 50.9 ± 19.3 years. The male/female ratio was 3:1. The incidence rate was between 0.41 and 0.65 cases per 100,000 person-years over the 18-year period. The highest incidence of cases was from March to August (p = 0.024). 21.1% patients had pneumonia, 17.5% had liver disease, and only 3.2% had endocarditis. The average hospital stay was 13.8 days (±12.8). A total of 117 (2.8%) patients died. The total mean cost of QF is approximately €154,232,779 (€36,600 ± 139,422 per patient). Conclusions: QF is an important zoonosis in Spain with a stable incidence rate and high cost for hospitalization. Older patients have a more severe clinical picture and higher mortality, which can be decreased with early clinical suspicion. Keywords: Q fever, Coxiella burnetii, Zoonosis, Pneumonia, Hepatitis, Epidemiology