Iron deficiency is common in haemodialysis patients and adequate supplementation by the oral or parenteral route has been limited by drug side-effects, absorption, and cost. Intermittent doses of intravenous iron dextran complex are recommended in patients with inadequate iron stores despite maximal tolerated oral dose. We conducted a prospective study with economic analysis of a regular maintenance intravenous iron regimen in this group of patients. Fifty patients comprising one-half of our haemodialysis population required intravenous iron treatment, i.e. they failed to achieve an arbitrary goal serum ferritin 100 microg/l despite maximal tolerated oral iron dose. After a loading dose of intravenous iron dextran complex (IV-FeD) based on Van Wyck's nomogram (400+/-300 mg) they received a maintenance dose of 100mg IV-FeD once every 2 weeks. Initial goal serum ferritin was set at 100-200 microg/l. If no increase in haemoglobin was achieved at this level, transferrin saturation was measured to assess bioavailable iron, and when less than 20%, goal serum ferritin was increased to 200-300 microg/l. Recombinant human erythropoietin (rHuEpo) was used where needed to maintain haemoglobin in the 9.5-10.5 g/l range only if ferritin requirements were met. Results. Mean haemoglobin rose from 87.7+/-12.1 to 100.3+/-13.1 g/l (P<0.001, Cl 7.7-17.9) at mean follow-up of 6 months (range 3-15 months). In patients on rHuEpo, dose per patient was reduced from 96+/-59 u/kg per week to 63+/-41 u/kg per week, representing a 35% dose reduction (P<0.05, Cl 1-65). An annual cost reduction of $3166 CDN was projected; however, in the first year this is offset by the cost of the loading dose of IV-FeD required at the beginning of treatment. No adverse reactions were encountered. Iron deficiency is very common in our haemodialysis population, especially in those patients receiving rHuEpo. A carefully monitored regimen of maintenance parenteral iron is a safe, effective, and economically favourable means of iron supplementation in patients with insufficient iron stores on maximum tolerated oral supplements.