All adult patients from 13 dialysis centres were prospectively followed up for 6 months in an attempt to appraise the current risk factors for bacterial infections in stable chronically haemodialysed patients. Parameters recorded as potential risk factors for BI were age, gender, cause of renal failure, time elapsed since the start of dialysis, history of transplantation, recent surgical procedure, previous bacterial infection, current immunosuppressive or erythropoietin therapy, type of angioaccess device, and serum ferritin level. Six hundred and seven patients (mean age 56.5 years, range 18-85) were enrolled in the study. Mean time elapsed since the start of dialysis was 4.7 years. One hundred and eighteen patients had developed at least one bacterial infection during the study period whereas 489 had remained free of bacterial infection at the end of the follow-up. In multivariate analysis three parameters were found to be significant and independent risk factors for bacterial infection: previous history of bacterial infection (at least one versus no previous episode), type of angioaccess device (catheter versus native fistula), and elevated serum ferritin level (greater versus lower than 500 micrograms/l). These results support the evidence that impaired host defences in chronic haemodialysis patients may be secondary to the dialysis procedure and suggest that the incidence of bacterial infection in these patients may be further reduced by appropriate supportive therapy.