BACKGROUND: This study was aimed to investigate the risk factors for mortality in patients with COVID-19. METHODS: For this retrospective cohort study, we included 121 deceased and 436 discharged cases with COVID-19 in Babol, Northern Iran. The cases were between March 1 to April 1, 2020. RESULTS: Multivariate Poisson regression analysis revealed that older age (aRR: 1.03, 95% CI: 1.01, 1.05, p < 0.001), hospital length of stay (aRR: 0.94, 95% CI: 0.90, 0.97, p = 0.003), ICU admission (aRR: 4.34, 95% CI: 2.95, 6.37, p < 0.001), cerebrovascular disease (aRR: 1.96, 95% CI: 1.20, 3.19, p = 0.007), ventilator-associated pneumonia (VAP) (aRR: 2.09, 95% CI: 1.22, 3.55, p = 0.006), septic shock (aRR: 2.98, 95% CI: 1.44, 6.19, p = 0.003), acute respiratory distress syndrome (ARDS) (aRR: 3.80, 95% CI: 2.28, 6.31, p < 0.001), acute kidney failure (AKF) (aRR: 1.45, 95% CI: 1.12, 3.76, p = 0.021), acute heart failure (AHF) (aRR: 1.63, 95% CI: 1.01, 2.62, p = 0.043) and lymphocyte count (aRR: 3.01, 95% CI: 1.99, 4.57, p < 0.001) were associated with mortality. CONCLUSION: Findings showed that elderly with comorbidities such as cerebrovascular diseases had an increased risk of death. Some complications such as: pneumonia, septic shock, ARDS, AHF, and AKF played crucial roles as well death (Tab. 2, Ref. 25).