Background: Mucormycosis is a worldwide angio-invasive fungal infection that is associated with high morbidity and mortality. A few European studies have focused on the epidemiology. Methodology: A retrospective longitudinal descriptive study was performed with inpatients diagnosed with mucormycosis (ICD-9-CM, code 117.7, cases 1997-2015; and ICD-10, code B46, cases 2016-2018; along with length of hospital stay) in Spanish public hospitals between 1 January 1997 and 31 December 2018. Data were obtained from the Minimum Basic Data Set (CMBD in Spanish). Principal findings: A total of 962 patients were recorded; 665 were men. The mean age (±SD) was 55±18.8 years. The annual incidence rate increased from 0.74 to 1.24 cases per million person-years. The lethality rate was 31.3%. Renal failure (41.6%) and hematological malignancy (36.3%) were the main factors involved. Conclusions: Mucormycosis is a rare infectious disease in Spain, but it has had a significantly increased incidence in the last two decades. Being an adult male and having diabetes, neoplasm or renal failure are the main factors associated. High mortality is usually associated mainly with hematological malignancy and renal failure. CMBD studies could be an efficient tool for assessing changes in the epidemiology of mucormycosis.