The effect of corticosteroid therapy is still controversial on prevention of mortality in coronavirus disease-2019 (COVID-19). The objective of this study is to investigate the effect of corticosteroids on mortality. This systematic review was performed as per preferred reporting items for systematic reviews and meta-analyses guidelines. A systematic search was performed at different databases namely Medline/PubMed, Cochrane and Google scholar on 10 February 2022. A pooled estimate for effect of corticosteroid therapy on mortality was calculated as outcome of study. Risk bias analysis and Newcastle Ottawa Scale were used to assess the quality of randomized control trial (RCT) and cohort studies, respectively. Cochran's Q test and the I² statistic were conducted for heterogeneity and accordingly study model was applied. A total 43 studies were included, having sample size of 96,852 patients. Amongst them, 19,426 and 77,426 patients received corticosteroid therapy (intervention group) or standard treatment without corticosteroid (control group), respectively. Mortality observed in the intervention and control group was 14.2% (2749) and 7.1% (5459), respectively. The pooled estimate 2.173 (95% CI: 2.0690–2.2820) showed significantly increased mortality in intervention as compared to control. The pooled estimate of methyprednisolone 1.206 (95% CI: 1.0770–1.3500) showed significantly increased mortality while the pooled estimate of dexamethasone 1.040 (95% CI: 0.9459–1.1440) showed insignificantly increased mortality as compared to control. In conclusion, corticosteroid therapy produced a negative prognosis as depicted by increased mortality among COVID-19 patients. The possible reasons might be delay in virus clearance and secondary infections due to corticosteroids initiated at high dose in the early stage of infection.