Since 1974 we have entered 12 children with sickle cell disease and strokes on a transfusion protocol to maintain hemoglobin S less than 20%. Serial arteriography, EEGs, brain or CT scans, and neuropsychologic testing were also obtained. Transfusion has been stopped in ten patients after one to two years. Seven of these ten patients have had second strokes five weeks to 11 months after cessation of transfusion (median three months). Arteriography was normal at the time of the initial stroke in two patients; one of these had a second stroke. Arteriograms did not improve during transfusion therapy. EEGs and brain and CT scans were occasionally useful at the time of the initial stroke but were of little value in following these patients. Neuropsychologic testing indicated severe impairment of sensory-motor and cognitive processes at the time of the initial stroke and was useful in following improvement or deterioration and in designing remedial education programs. We conclude that short-term transfusion therapy will not prevent second strokes once transfusion is stopped and that arteriography is of limited value in these patients.