Background/purpose: The relationship between liver injury and mortality remains unclear in patients with COVID-19. We aimed to evaluate the prognostic value of aminotransferases levels at hospital admission to predict mortality in patients with COVID-19. Methods and results: This prospective study included 406 patients [57% male, aged 56 years] with COVID-19 hospitalized in 26 centers in Brazil. Overall, 36.7% (95% CI 32.1–41.5) presented at admission with severe disease requiring respiratory support. The prevalence of elevated ALT and AST levels at admission [> 2 × ULN] was 14.0% (95% CI 11.0–17.8) and 12.9% (95% CI 10.0–16.6), respectively. Sixty-two patients [15.3% (95% CI 12.1–19.1)] died during hospitalization and the overall mortality rate was 13.4 (10.5–17.2) deaths per 1000 persons-years. The 15-day-overall survival (95% CI) was significantly lower in patients with ALT levels ≥ 2 × ULN compared to those with ALT < 2 × ULN [67.1% (48.4–80.2) vs 83.4% (76.1–88.6), p = 0.001] and in those with AST levels ≥ 2 × ULN compared to those with AST < 2 × ULN [61.5% (44.7–74.6) vs 84.2% (76.5–89.5), p < 0.001]. The presence of elevated aminotransferases levels at hospital admission significantly increased the risk of in-hospital all-cause mortality adjusted for age-and-sex. Those findings were present in the subgroup of critically ill patients already admitted in need of respiratory support (n = 149), but not in patients without that requirement at admission (n = 257). Conclusions: Elevated aminotransferases at hospital admission predicted in-hospital all-cause mortality in patients with COVID-19, especially in those with severe disease. Measurement of transaminases levels at hospital admission should be integrated to the care of patients with COVID-19 as an auxiliary strategy to identify patients at higher death risk.