16 arteritic patients at stages II, III or IV according to Fontaine's ranking system were treated by normovolemic hemodilution (HDN). The procedure consisted of the daily withdrawal of 500 ml of blood, which was replaced by 250 ml of a 4% solution of human albumin and 250 ml of Dextran 40. The procedure was applied, on average, for three days in succession until the patient's hematocrit reached 0.30. The therapy was carried out over a total of 8 weeks in order to maintain hematocrit levels at between 0.30 and 0.35. Improvement was observed in clinical factors: a 100% increase in walking perimeter in stage II patients, disappearance of decubitus pain in stage III patients, wound healings in stage IV patients. The following rheological and platelet parameters were studied: plasma and blood viscosity with hematocrit level 0.40 and for seven speed of scissoring, red blood cell aggregation index, platelet aggregation, MDA platelet levels, plasma BTG. Clinical results revealed that by the 56th day of treatment, 8 patients had improved and 8 remained stationary (the condition of 3 of the "stationary" patients in fact worsened having evolved according to the normal development of arteritic disease). The improvements observed persist several months after normovolemic hemodilution has been discontinued, with the results for the longest studied patient going back as far as 15 months. With regard to the hemorheological parameters (which, on Day 0, are always disturbed), they tend to improve during the hospitalization period and stabilize at levels lying between the values measured on Day 0 and normal values.(ABSTRACT TRUNCATED AT 250 WORDS)