Sickle cell anemia (SCA) is an inherited disease characterized by a complex and varied physiopathology and exhibits wide clinical diversity. SCA’s variability poses significant management challenges to caregivers and physicians alike. Different scoring systems have been used for the assessment of the severity of the disease since evaluation of disease severity in patients with SCA will help to identify patients at higher risk for an adverse clinical course who may need more active management and monitoring. In this study we tried to introduce a modified scoring system to evaluate the clinical severity of SCA in Sudanese patients using simple clinico-pathological parameters linking clinical severity to some hematological parameters. The total severity score of the 131 patients studied ranged from 1 to 19, with mean±standard deviation of (11.7±4.91) and median of 12.0. One hundred and three patients (78.6%) had either moderate disease 87 (66.4%) or severe disease 16 (12.2%), while 28 (21.4%) had mild disease according to this severity score grading system. Among the severe group the frequency of males was 3 times that of females. Dactylitisas the first manifestation of disease revealed the highest frequency and almost all of the affected patients (44/49) had moderate and severe disease. Total white blood cell count and absolute neutrophil count were significantly higher while hemoglobin concentration was significantly lower among those with severe disease.