•SARS-CoV-2, the cause of COVID19 disease, has spread globally since late 2019•Bacterial coinfections associated with mortality in previous influenza pandemics•Proportion of COVID19 patients with bacterial coinfection less than in flu pandemics•Higher proportion of critically-ill with bacterial coinfections than in mixed setting•Bacterial co-pathogen profiles different to those in influenza co-infections•Fungal coinfection diagnosis difficult so high level suspicion in critically-ill In previous influenza pandemics, bacterial co-infections have been a major cause of mortality. We aimed to evaluate the burden of co-infections in patients with COVID-19. We systematically searched Embase, Medline, Cochrane Library, LILACS and CINAHL for eligible studies published from 1 January 2020 to 17 April 2020. We included patients of all ages, in all settings. The main outcome was the proportion of patients with a bacterial, fungal or viral co-infection. . Thirty studies including 3834 patients were included. Overall, 7% of hospitalised COVID-19 patients had a bacterial co-infection (95% CI 3-12%, n=2183, I2=92·2%). A higher proportion of ICU patients had bacterial co-infections than patients in mixed ward/ICU settings (14%, 95% CI 5-26, I2=74·7% versus 4%, 95% CI 1-9, I2= 91·7%). The commonest bacteria were Mycoplasma pneumonia, Pseudomonas aeruginosa and Haemophilus influenzae. The pooled proportion with a viral co-infection was 3% (95% CI 1-6, n=1014, I2=62·3%), with Respiratory Syncytial Virus and influenza A the commonest. Three studies reported fungal co-infections. A low proportion of COVID-19 patients have a bacterial co-infection; less than in previous influenza pandemics. These findings do not support the routine use of antibiotics in the management of confirmed COVID-19 infection.