Objectives: Painful crisis is a significant problem for patients with sickle cell diseases (SCD). We tried to understand whether or not there is an association between severity of pain and complication rate in hospitalized children and adolescents with SCD in the present study.Methods: All hospitalized SCD patients with painful crisis between September 2012 and September 2013 were included into the study. The intensity of pain was assessed at the first visit. Pain scores were obtained using the Faces Pain scale and Verbal Descriptor Scale. Severity of pain was divided into three groups as mild, moderate, and severe according to the scales.Results: Seventy-nine patients under the age of 18 years-old with SCD and 146 episodes of painful crisis were evaluated. Forty-five (57%) patients were women and mean age was 11.5 years. The white blood cell counts, aspartate aminotransferase and C-reactive protein (CRP) were significantly higher while erythrocytes, hemoglobin, hematocrit and albumin levels were significantly lower in the severe pain episodes group (p<0.05 for all). The number of patients transfused was significantly high in the severe pain episodes group than the other two groups (p=0.006, p=0.001). Most of severe pain episodes group had complicated vaso-occlusive crisis (acute chest syndrome 41.6 %, Hepatic sequestration crisis 6.7%), (p<0.05).Conclusion: There may be an direct relationship between prevalence of complicated vaso-occlusive crisis and pain intensity of SCD. Patients with sickle cell anemia should be classified according to their pain scores during hospitalization, and patients with high pain scores should be closely monitored for complications.