Quantitative whole-body linear profile scans of 59Fe, obtained by a whole-body counter, conventional ferrokinetics and hematological parameters are investigated in patients (n = 208) with various hematological-oncological diseases. Linear whole-body profile scans in controls, obtained 24 h after i.v. injection of 59Fe-transferrin, give quantitative information about sites of the erythropoietic system. Early profile scans (1 h p.i.) in patients with anemia show a typical 'iron-suction' corresponding to the fast outflow of 59Fe from the blood compartment. We found no typical change of iron distribution in Hodgkin and Non-Hodgkin lymphomas, even in patients with anemia or hemolysis there was no evidence of expansion of erythropoiesis to distal marrow sites. Our investigation does not contribute to staging of patients with Hodgkin's disease. Osteomyelofibrosis is characterized by a centrifugally expanded erythropoiesis. The value of increased iron uptake 24 h p.i. in leg regions for differential diagnosis of hemolytic anemia, chronic myelocytic leukemia, and pancytopenia where a similar pattern of iron distribution is observed will be discussed. Quantitative iron kinetics with one dimensional 59Fe profile scans give additional information in patients with displaced erythropoietic system.