In a survey of more than 12,000 persons referred to a hematological outpatient clinic in Algiers, we estimated that the incidence of hereditary spherocytosis (HS) is 1/1000. Another 9 cases were found in nine of the corresponding families. Anemia was present in a total of 44 subjects (81%). The transmission was dominant in five of eight informative families (63%). No firm conclusion could be reached concerning the amount of spectrin and ankyrin in nine families; however two-dimensional peptide maps ruled out any alphaII domain abnormality in these families. We estimate that HS has roughly the same incidence and features among Algerians as in Europeans or people of European descent.