Intravenous iron preparations have shown benefit in patients with chronic heart failure (CHF) and iron deficiency. Iron isomaltoside 1000 (Monofer) is a novel intravenous iron compound with low immunological activity of the isomaltoside and low free-iron-related toxicity. The primary objective of this open-label, non-comparative, multicenter pilot study was to test the safety of iron isomaltoside 1000 in patients with CHF and anemia. In addition, its effect on markers of iron deficiency, anemia and on quality of life was assessed. Twenty patients with CHF and iron deficiency anemia attended six visits during the 8-week study period. Iron isomaltoside 1000 was infused at baseline (mean dose 868mg, range 650-1000mg). No treatment-related adverse reactions, no acute anaphylactic or delayed allergic reactions and no clinically significant changes in routine clinical laboratory safety tests or vital signs were observed. Markers of iron deficiency, anemia and quality of life improved from baseline with increase in mean value of 49% at 4 weeks in overall quality of life. Iron isomaltoside 1000 administered as a fast single infusion without a test dose to patients with CHF improved quality-of-life assessments and was well tolerated in this pilot safety study.