Hand films of 100 patients with sickle cell disease were analyzed in order to establish the type, distribution, and incidence of terminal phalangeal sclerosis. Fifty hand films from patients with no known sickle cell disease matched for age and race were also studied. Twenty-four of 100 patients with sickle cell disease, with 14 less than 20 years old, showed clear evidence of terminal phalangeal sclerosis, while only 10% of the controls were positive. The incidence was significantly different from the control group (chi 2 = 4.1949, d.f. = 1, p less than 0.05) suggesting that terminal phalangeal sclerosis is a significant finding in a young patient with sickle cell disease.