peer reviewed ; Objectives: The aim of this study is to provide relevant and accurate information on prevalence and treatment patterns of anaemia in Belgian cancer patients. Methods The Anaemia Day 2008 survey was a single visit, multi-centre, non-interventional study in adult cancer patients under systemic therapy (chemotherapy, hormonal, immunological and/or targeted therapy) and/or radiotherapy. Efforts were made to enrol the maximum number of patients seen in each centre that day. Patients signed an informed consent and relevant data were collected from their files, i.e. disease and disease stage, cancer therapy and anti-anaemic treatment, including transfusions and the use of erythropoietin stimulating agents (ESA). A blood count of each included patient was performed. Haemoglobin (Hb) values (grams per decilitre) were classified into four categories to assess the severity of anaemia, as defined byWHO: no anaemia: Hb≥12 g/dL; mild 10≤Hb≤11.9 g/dL; moderate 8≤Hb≤9.9 g/dL; severe Hb< 8 g/dL. Univariate and multivariate analyses were carried out with anaemia as the dependent variable. Results A total of 1,403 eligible patients aged 63±13 years (mean age±SD) were enrolled in 106 oncology or haematology centres. The mean Hb level (±SD) was 11.6 g/dL (±1.8 g/dL) and the prevalence of anaemia (Hb<12 g/dL) was 55.7% (95% CI, 53.1–58.3%), respectively, 35.9% mild, 17.8% moderate and 2.1% severe anaemia. Anaemia was more frequent in females than in males, and in patients with haematological malignancies (73.4%) than in those with solid tumours (51.4%; p<0.001). Anaemia prevalence was higher in hospitalised patients (75.5%) compared to those seen in one-day-clinic (54.3%) or in consultation (33.9%; p<0.001), and in patients treated with chemotherapy (61.3%) compared to those receiving radiotherapy (34.4%) or hormonal therapy (19.5%; p<0.001). There was a clear correlation between severity of anaemia and WHO performance status (p< 0.001). Among anaemic patients, 53.1% received no treatment (mean Hb ...