Some children and adolescents with sickle cell disease experience frequent painful episodes. To gain information about the natural history of the pain and its impact on sleep and school attendance, we developed a home-based diary system. Eighteen children and adolescents completed 4756 diary days, with an average compliance of 75%. Pain was reported on 30% of days and was managed at home nine-tenths of the time. Girls reported more days with pain than did boys, and age was positively correlated with the length of the painful episodes. The pain affected school attendance and sleep. Patients were absent from school on 21% of 3186 school days, with half of the absenteeisms on days with reported pain. Of the pain-associated absenteeisms, two-thirds occurred when pain was managed at home, and one-third when patients were hospitalized. The average consecutive number of school days missed was 2.7. These findings have implications for developmentally critical activities.