A better understanding of the context-specific epidemiology, outcomes, and risk factors for death of critically ill parturients in resource-poor hospitals is needed to tackle the still alarming in-hospital maternal mortality in African countries. From October 2017 to October 2018, we performed a 1-year retrospective cohort study in a referral maternity hospital in Freetown, Sierra Leone. The primary endpoint was the association between risk factors and high-dependency unit (HDU) mortality. Five hundred twenty-three patients (median age 25 years, interquartile range [IQR]: 21-30 years) were admitted to the HDU for a median of 2 (IQR: 1-3) days. Among them, 65% were referred with a red obstetric early warning score (OEWS) code, representing 1.17 cases per HDU bed per week; 11% of patients died in HDU, mostly in the first 24 hours from admission. The factors independently associated with HDU mortality were ward rather than postoperative referrals (odds ratio [OR]: 3.21; 95% CI: 1.48-7.01; P = 0.003); admissions with red (high impairment of patients' vital signs) versus yellow (impairment of vital signs) or green (little or no impairment of patients' vital signs) OEWS (OR: 3.66; 95% CI: 1.15-16.96; P = 0.04); responsiveness to pain or unresponsiveness on the alert, voice, pain unresponsive scale (OR: 5.25; 95% CI: 2.64-10.94; P ≤ 0.0001); and use of vasopressors (OR: 3.24; 95% CI: 1.32-7.66; P = 0.008). Critically ill parturients were predominantly referred with a red OEWS code and usually required intermediate care for 48 hours. Despite the provided interventions, death in the HDU was frequent, affecting one of 10 critically ill parturients. Medical admission, a red OEWS code, and a poor neurological and hemodynamic status were independently associated with mortality, whereas adequate oxygenation was associated with survival.