The main point of oncology ethics is the patient-physician relationship. Honesty, confidence and sharing responsibility are the critical points of this relationship. Coping with cancer diagnosis and transduction to the treatment process requires a strong patient-physician relationship. Accurate communication, evaluation of patients from the psychosocial point of view and analysis of patient's expectancy are effective in identifying the most proper relationship model for the patient. Problems that may appear in the relationship between cancer patient and physician originate from the patient, disease characteristics, physician's approach, and external factors such as deficiency of substructure-staff-equipment, extreme workload of the physician, poor hospital management and financial problems. Eradication of the external factors is related to the health policy of the state, but accurate communication must take part in the professional skills of the physician.