Objectives: Reactive haemophagocytic syndrome (RHS) is a hyperinflammatory disorder often occurring in the background of several disorders such as infections, malignancies, and rheumatic diseases. Recently, a score known as the HScore was developed for the diagnosis of RHS. In the original study, most of the patients had underlying haematological malignancy or infection and the best cut-off value for the HScore was 169 (sensitivity 93%; specificity 86%). In this study we aimed to analyse the performance of the HScore in rheumatic disease-related RHS.Method: The patients with rheumatic disorders evaluated in the Departments of Rheumatology and Paediatric Rheumatology at Hacettepe University, Ankara, Turkey between 2002 and 2014 were reviewed retrospectively. The first group (n=30) consisted of patients with RHS; the control group (n=64) included patients with active rheumatic diseases without RHS.Results: In the RHS group, 14 (46.7%) had adult-onset Still's disease (AOSD), 10 (33.3%) systemic juvenile idiopathic arthritis (SJIA), and six (20%) systemic lupus erythematosus (SLE). The control group (n=64) consisted of 32 (50%) AOSD, 13 (20.3%) SJIA, and 19 (29.7%) SLE patients. Applying the HScore to the RHS patients, the best cut-off value was 190.5 with a sensitivity of 96.7% and specificity of 98.4%. When we excluded the patients from the control group who had not had bone marrow aspiration (n=23), the same cut-off (190.5) performed best (sensitivity 96.7%; specificity 97.6%). Applying the 2004 haemophagocytic lymphohistiocytosis (HLH-2004) criteria gave a sensitivity of 56.6% and a specificity of 100% in the whole study group.Conclusions: In our study, a cut-off value for the HScore different from the original study performed better. Further studies are warranted to determine optimum cut-off values in different studies.