The long-term effects of COVID-19 remain largely unclear. This study aims to investigate post-acute health consequences and mortality one year after hospital discharge. All surviving adult patients who were discharged after hospital admission due to acute COVID-19 in the first wave of the pandemic underwent a comprehensive interview. Functional assessment was performed in patients aged over 65. Clinical and hospital records were reviewed and mortality causes assessed. A total of 587 patients with COVID-19 were discharged from hospital, including 266 after hospital admission and 321 from the emergency room. Mortality within the following year occurred in 34/266 (12.8%) and 10/321 (3.1%), respectively, due to causes directly or possibly related to COVID-19 in 20.5% and 25% of patients. Post-COVID-19 syndrome was assessed in 543 patients at one year from discharge. Any clinical complaint was reported by 90.1% of patients who needed hospitalization and 80.4% of those discharged from the emergency room (p = 0.002), with breathlessness (41.6%), tiredness (35.4%), ageusia (30.2%), and anosmia (26.3%) being the most common complaints. Ongoing symptoms attributed to COVID-19 were reported by 66.8% and 49.5% of patients, respectively (p < 0.001). Newly developed COPD, asthma, diabetes, heart failure, and arthritis—as well as worsening of preexisting comorbidities—were found. One-year mortality among survivors of acute COVID-19 was 7.5%. A significant proportion of COVID-19 patients experienced ongoing symptoms at 1 year from onset of the disease.