Gastrointestinal complications are important causes of morbidity and mortality in patients with acute leukaemia. However, no adequate reports exist regarding safety and usefulness of endoscopies. We present a retrospective series of consecutive patients in whom upper or lower gastrointestinal endoscopies or ERCP were performed after 117 of 1640 cycles of myelosuppressive chemotherapy. The most frequent findings of upper endoscopies were: Oesophagitis (50.9%), gastric erosions (30.2%), hiatus hernia (24.5%) and gastritis (22.6%). Upper endoscopies had therapeutic consequences in 55%. Endoscopy could be performed relatively safely but the percentage of patients in whom endoscopic haemostasis was applicable and effective was low.