Introduction : COVID-19 has been characterized by a wide spectrum of manifestations and clinical forms that range from mild illness to death. Identifying those most likely to develop complications is critical. Objective : To identify risk factors for developing complications in patients treated with COVID-19. Methods : 250 medical records of patients admitted for COVID-19 were reviewed. Age, sex, personal pathological history, laboratory tests and the presence or absence of complications were collected. Chi-square was used to identify the relationship between complications and sex. The Odds Ratio (OR) was calculated for complications by age groups, personal pathological history, and humoral parameters. Results : Respiratory distress was more frequent in men (p=0.023). The most affected age groups were 60 to 79 years and 80 years and over (OR=4.85 and 30.53 respectively). Risk factors were the history of arterial hypertension, ischemic heart disease, diabetes mellitus, chronic kidney insufficiency and dementia (OR=4.48, 4.22, 8.75, 17.98 and 10.39 respectively). Low hematocrit and lymphocytes were predisposed to complications, as well as high neutrophils, glycaemia, creatinine, ASAT, GGT and LDH. Conclusions : The highest risk of complications was in patients older than 60 years, with cardiovascular diseases, diabetes mellitus, kidney insufficiency and dementia. The presence of low hematocrit and lymphocytes, or high neutrophils, glycaemia, creatinine, ASAT, GGT and LDH, alerts you to possible complications.