BACKGROUND: Sickle cell disease can cause severe vaso-occlusive crises and dysfunction of most organ systems. The two most common chronic chest complications due to sickle cell disease are pulmonary hypertension and chronic sickle lung disease. These complications can lead to morbidity (such as reduced exercise tolerance) and increased mortality. OBJECTIVES: The aim of this review is to find out whether trials involving people with sickle cell disease that compare regular long-term blood transfusion regimens with an alternative treatment or no treatment show differences in the following:1. the incidence of chronic chest complications (chronic sickle lung disease or pulmonary hypertension);2. the ‘severity’ or progression of established chronic chest complications;3. the mortality associated with chronic chest complications; and4. unacceptable adverse events. SEARCH METHODS: We searched the Group’s Haemoglobinopathies Trials Register. Specific websites were also searched for information of ongoing or newly completed trials. The search included the reference lists of any randomised controlled trials identified using the above methods.Date of the most recent search of the Cochrane Cystic Fibrosis and Genetic Disorders Group’s Haemoglobinopathies Trials Register: 22 July 2013. SELECTION CRITERIA: We included randomized controlled trials. Trials that used quasi-randomized methods were to be included if sufficient evidence existed that the treatment and control groups were similar at baseline. Trials were eligible for inclusion if they investigated regular red blood cell transfusion regimens (either simple top-up or exchange transfusions) aimed at reducing the incidence, mortality, or objective measures of severity or progression of chronic chest complications (chronic sickle lung and pulmonary hypertension) among men or women of any age and with one of four common sickle cell disease genotypes, ie Hb SS, Sß(0), SC, or Sß(+). These interventions would be compared to an alternative treatment with the same aim or to no treatment. DATA COLLECTION AND ANALYSIS: No studies matching the selection criteria were found. MAIN RESULTS: No studies matching the selection criteria were found. AUTHORS' CONCLUSIONS: There is a need for randomized controlled trials looking at the role of long-term transfusion therapy in pulmonary hypertension and chronic sickle lung disease. Due to the chronic nature of the conditions, such trials should aim to use a combination of objective and subjective measures to assess participants during an extended ‘steady state’ baseline, and after the intervention.