The objectives of this phenomenological research were to describe and discuss about experiences and factors affecting relatives of head and neck cancer patients receiving radiotherapy and staying at Yensira Hostel in helping to care for them. The study was conducted by using purposive in-depth interviews with relatives taking care of head and neck cancer patients receiving radiotherapy and staying at Yensira Hostel during December 2002 and April 2003. The data were analyzed using Colaizzi's qualitative analysis method. The results could be divided into five areas. 1) The relatives' perception about the meaning and methods in caring for patients. The meaning of care was perceived in two ways: (1) to help patients in every matter to make them comfortable physically and mentally and (2) to help patients in what they could not do by themselves. For methods of caring, most relatives were concerned about both physical and mental aspects. 2) Experiences of relatives in caring for patients. It was found that the experiences of relatives of head and neck cancer patients receiving radiotherapy were in three categories: (1) adapting themselves to the way of life that had changed, (2) learning how to care for the patients from many sources, and (3) needing hope and encouragement in the caring. 3) The feeling towards giving care to the patients. This could be categorized into 6 types: (1) the feeling of being isolated from families and acquaintances, (2) worries about the condition of the patients, (3) the feeling that it is a burden, (4) feeling like being cornered to do it with no way out, (5) unwillingness to do it but having to because it was a responsibility, and (6) the feeling that the patients were not safe staying at Yensira Hostel. 4) Problems and obstacles that the relatives faced in caring for the patients could be classified into 11 types: (1) misunderstanding and conflicts with the patients, (2) inability to communicate inhibitiryan understanding, (3) financial and work problems which decreased moral strength, (4) patients becoming under emergency condition while staying there, (5) being old making it physically difficult to care for the patients, (6) becoming sick while taking care of patients, (7) deserting the patients to go with their girlfriend, (8) being stressful resulting from many causes, (9) language problems which obstructed the learning, (10) the absence of physicians to care for the patients when the primary responsible person was away, and (11) traveling to the hospital made the patients with severe condition suffered. 5) The relatives' self adaptation and coping with problems. These could be classified into 8 aspects: (1) seeking knowledge, (2) being patient, (3) trying to understand and admit them, (4) building strength in themselves on their own, (5) having support from the society, (6) turning to spiritual support, (7) moderating their emotion, and (8) keeping themselves busy with work. The results of this study could be used in planning for the hospital services in four areas: 1) the service system that caters for patients and their relatives staying temporarily at Yensira Hostel, 2) setting up guidelines for practice to enable the relatives to feel more secure in caring for the patients at Yensira Hostel, 3) finding ways and resources to help relieve problems for the relatives during the care for the patients, and 4) giving reasons why it is necessary for the patients to stay at Yensira Hostel.