Background. There are few descriptions of the clinical presentation and evolution of consecutive SARS-CoV-2 infections with a long-enough follow up. Methods. Description of the first consecutive 100 patients with microbiologically-proven COVID-19 in a large hospital in Madrid, Spain including a minimum of two-month follow up. Results. The median age of the patients (52% males) was 61.5 years (IQR=39.5-82.0) and the median BMI was 28.8 kg/m2 (IQR=24.7-33.7). Overall 72% of the patients had one or more co-morbid conditions with a median age-adjusted Charlson index of 2 (IQR=0-5.7). Five patients (5%) were immunosuppressed. The most common symptoms at the time of diagnosis were fever (80.0%), cough (53.0%) and dyspnea (23.0%). The median O2 saturation at the time of first examination was 94% (IQR=90-97). Chest X-ray on admission was compatible with pneumonia in 63% of the cases (bilateral in 42% and unilateral in 21%). Overall, 30% were managed at home and 70% were admitted to the hospital. Thirteen patients were admitted to the ICU with a median of 11 days of stay in the Unit (IQR=6.0-28.0). CALL score of our population ranged from 4 to 13. Overall, 60.0% of patients received antibiotic treatment and 66.0%, empirical antiviral treatment, mainly with lopinavir/ritonavir (65%) or hydroxychloroquine (42%). Mortality, with a minimum of 60 days of follow up, was 23%. The median age of the deceased patients was 85 years (IQR=79-93). Conclusions. We found a high mortality in the first 100 patients diagnosed with COVID-19 at our institution, associated with advanced age and the presence of serious underlying diseases.