Introduction: An epidemic of Coronavirus Disease 2019 (COVID-19) begun in December 2019 in China, causing primary concern. Among raised questions, clinical, laboratory, and imaging features have been partially characterized in some observational studies. No systematic reviews have been published on this matter. Methods: We performed a systematic review of the literature with meta-analysis, using three databases to assess clinical, laboratory, imaging features, and outcomes of confirmed cases of COVID-19. All the observational studies, and also case reports, were included. The case reports were analyzed separately. We performed a random-effects model meta-analysis to calculate the pooled prevalence and 95%CI. Measures of heterogeneity, including Cochran’s Q statistic, the I2 index, and the τ2 test, were estimated and reported.Results: 660 articles were retrieved. After screening by abstract and title, 27 articles were selected for full-text assessment. Of them, 19 were finally included for qualitative and quantitative analyses. Additionally, 39 case report articles were included and analyzed separately. For >656 patients, fever (88.7%, 95%CI 84.5-92.9%), cough (57.6%, 40.8-74.4%) and dyspnea (45.6%, 10.9-80.4%) were the most prevalent clinical manifestations. Among the patients, 20.3% (95%CI 10.0-30.6%) required ICU, with 32.8% presenting ARDS (95%CI 13.7-51.8), 6.2% (95%CI 3.1-9.3) with shock and 13.9% (95%CI 6.2-21.5%) with a fatal outcome.Discussion: COVID-19 is a new clinical infectious disease, causing considerable compromise, especially in patients with comorbidities, requiring ICU in at least a fifth of them and sometimes with fatal outcomes. Additional research is needed to elucidate factors that may mediate the pathogenesis of the severe and fatal associated disease.