SummaryThe increment in the number of patients to be treated in Belgium by chronic hemodialysis over the next five years is evaluated. The influence of the age limits set for therapy and of the number of transplantations performed annually is analyzed. Over the next five years the presently available facilities will have to be multiplied by 3 if all patients from 15 to 55 years are treated and by 5 if these age limits are extended to 65 years.Within our model the influence of annual transplantation rate on the five year requirements for chronic dialysis is very limited. This will be even more pronounced if dialysis is extended to older, not transplantable patients. The necessity to expand home dialysis and to decrease the cost of dialysis is emphasized. Without such efforts it might become financially difficult to treat all patients up to 55 or 65 years of age.