Throughout the world medical practitioners recognize that adherence to medical treatment by the chronically ill is a substantial problem (World Health Organization, 2003). This study defines medical treatment adherence in a well-characterized hemophilia population through the multiple perspectives of patients, family caregivers, and medical professionals Methods. Focus groups were used to develop adherence survey instruments that were administered along with standardized medical outcome surveys. Patient infusion and factor dispensing logs were used to establish adherence scores. Correlation and one-way analysis of variance were used to analyze the data Results. (1) Low Adhering Patients: (a) felt that recognition of their knowledge about the disease by medical practitioners would help them adhere, (b) they also worried about treatment costs. (2) High Adhering Patients: (a) understood the severity of their disease, (b) scored lower on family cohesion, (c) found scheduling problems as a deterrent to adherence, and (d) scored their general health at lower levels. (3) The physical functioning for all patients fell below the national norm mean. (4) Parents thought their children had more pain than the children reported. (5) The children reported their overall general health to be higher than the national norm. (6) The mothers and children scored below the national norm mean for mental health. (7) The adults scored lower in mental health as their adherence level progressed Conclusions. Children are more optimistic about their health than adults. Practitioners can help by finding ways to recognize knowledge the patient has about the disease. Scheduling issues should be addressed in medical treatment planning. High adhering adult patients, mothers, and child patients may benefit from assistance with mental health issues as an adherence intervention