Introduction: The gravity of the clinical state of the patient of intensive care is linked to the existence of one or several lesions and visceral defaults putting its forecast into play. Objective: To determine the prognosis value of two general graveness’ scores of patients admitted to intensive care at University Hospital of Parakou in Benin. Patients and Methods: Descriptive and analytical observational study data were collected from March 1st to June 30th, 2017. The SAPS II and APACHE II were calculated during first 24 hours of hospitalization to assess the clinical graveness and predict patient’s mortality. Results: We enrolled 185 patients representing 89.37% of admissions, majority were men (63.78%). Mean age was 38.89 ± 17.92 years (16 to 99), mean of hospitalization duration was 4.36 ± 2.2 days. Neurological failure was the most common disorder observed (58.37%). Mean SAPS II and APACHE II were 29.54 ± 19.04 and 14.24 ± 10.49 respectively. Mean predicted mortality of SAPS II and APACHE II was 19.12 ± 5.05 and 25.69 ± 5.00 respectively. The mortality rate was 25.95% and increased with severity scores. The sensibility of APACHE II and SAPS II score was 72.90% and 66.70% respectively. SAPS II score was found to be more specific (85.40%) than APACHE II (80.03%). Conclusion: Those severity patient scores accurately predicted the prognosis of patients in intensive care unit and should be integrated into our practice.