Abstract Background The use of corticosteroids, specifically dexamethasone has been associated to low mortality in COVID-19 patients. We present here the mortality related to the use of corticosteroids in the first two months of the SARS-CoV-2 outbreak in México City. Methods We conducted a case series of patients with the diagnosis of pneumonia due to SARS-CoV-2 virus admitted to a tertiary care center in Mexico City, between March 14th and May 14th, 2020. Data collected included demographic information, comorbidities, treatment and outcomes including mortality. Results We included 109 patients with diagnosis of COVID-19 associated pneumonia with computed tomography; 76(69.7%) were male and 33(30.3%) female with a median age of 52 yo (24–85) and 51 yo (25–81), respectively. Most common comorbidities were overweight (48.6%), obesity (35.8%), hypertension (23.8%), and diabetes (18.3%). Thirty-eight patients received corticosteroids (Methylprednisolone 30, Hydrocortisone 6 and dexamethasone and prednisone in on case). Mortality in those that used corticosteroids was 21% (8/38) and 5.6% for those that did not received (4/71), p=0.014. Forty cases needed mechanical ventilation from the beginning, and 24 of those received corticosteroids with a mortality of 29% (7/24), while the mortality was 18.7% (3/16) in those with no steroid use, p=0.45. Conclusion Mortality in our small cohort with predominantly use of methylprednisolone is not lower in those using steroids. In fact, mortality was significantly higher in those that received corticosteroids, while this significance was not maintained in those that needed immediate mechanical ventilation. Use of corticosteroids for COVID-19 patients with pneumonia, should be further investigated. Disclosures All Authors: No reported disclosures