The authors describe the slow development of an abscess in the left subphrenic space in a patient with acute myeloid leukaemia. The patient suffered several months before the diagnosis was established from pain in the left subcostal region and was on account of this pain examined repeatedly by clinical methods and sonography. During the last sonographic examination in this area a hypoechogenic formation was detected. The diagnosis was than established more accurately by computer tomography by visualization of the abscess cavity. The case-history and relatively thick wall of the cavity suggested a long-term process. The abscess cavity was evacuated surgically, however, the patient suffered a relapse later and died from septicaemia. In the discussion the authors analyze the problem of development of metastatic abscesses in leukopenic patients, early diagnosis and treatment.