Computerized, semiquantitative image analysis of 2913 erythrocytes from 29 young patients with sickle cell anemia and its variants was conducted utilizing a modified method for determination of fetal hemoglobin distribution by an acid elution procedure. Histograms of eight arbitrary levels of staining intensity, proportional to fetal hemoglobin levels, were analyzed in relationship to both computer-generated, mathematical parameters of erythrocytic shape abnormalies and clinical parameters of disease severity. Shifts in fetal hemoglobin distribution were observed in analysis of sequential specimens. An inverse correlation was observed between angularity of erythrocytes and their individual fetal hemoglobin content (p⩽0.05). A positive correlation was noted between growth percentiles and percentage erythrocyte ghosts by acid elution (p⩽0.01).