Objectives: Sickle cell disease (SCD) is an inherited disease caused by an abnormal type of haemoglobin. It is one of the most common genetic blood disorders in the Gulf area, including Oman. It may be associated with complications requiring intensive care unit (ICU) admission. This study investigated the causes of ICU admission for SCD patients. Methods: This was a retrospective analysis of all adult patients ≥12 years old with SCD admitted to Sultan Qaboos University Hospital (SQUH) ICU between 1st January 2005 and 31st December 2009. Results: A total number of 49 sickle cell patients were admitted 56 times to ICU. The reasons for admission were acute chest syndrome (69.6%), painful crises (16.1%), multi-organ failure (7.1%) and others (7.2%). The mortality for SCD patients in our ICU was 16.1%. The haemoglobin (Hb) and Hb S levels at time of ICU admission were studied as predictors of mortality and neither showed statistical significance by Student’s t-test. The odds ratio, with 95% confidence intervals, was used to study other six organ supportive measures as predictors of mortality. The need for inotropic support and mechanical ventilation was a good predictor of mortality. While the need for non-invasive ventilation, haemofiltration, blood transfusions and exchange transfusions were not significant predictors of mortality. Conclusion: Acute chest syndrome is the main cause of ICU admission in SCD patient. Unlike other supportive measures, the use of inotropic support and/or mechanical ventilation is an indicator of high mortality rate SCD patient.