Of 391 patients with sickle cell disease known to the health care facilities of the University of South Alabama, 194 patients used these facilities in 1989. In that year, 33.5 percent of patients seen at the University of South Alabama did not attend the Comprehensive Health Care Clinics developed for sickle cell patients. There were major differences in the patterns of use and in health care costs among sickle cell patients who attended the Comprehensive Health Care Clinics and those who did not. Patients not using these clinics, although they accounted for only 33.5 percent of the total patients, constituted 71.4 percent of visits to the emergency rooms and 42.3 percent of inpatient admissions. Patients enrolled in the Comprehensive Health Care Clinics used emergency rooms and inpatient units less frequently (P < 0.0001 and P = 0.0006, respectively) and were responsible for significantly smaller health care costs in each category (P < 0.0300). Evaluation of factors responsible for differences in the use patterns and patient education to improve use of comprehensive health care services should be considered.