It is not unusual for patients with head and neck cancer (HNC) to suffer from both tumor and treatment-related pain that is difficult to alleviate despite individualized pharmacological treatment. The presence of concomitant various dimensions of pain in patients during the often difficult period following radiotherapy (RT) has not been elucidated. Several aspects concerning the importance of relatives for HNC patients have been addressed. However, little attention has been given to how relatives perceive patients with HNC pain and it is important to further elucidate this sparsely studied topic. Knowledge about health-related quality of life (HR-QoL) in this patient group during early RT is limited and needs to be assessed in relation to diagnosis and treatment. Self-care (SC) refers to what patients do on their own to achieve, maintain, and promote optimal health and may help reduce pain for several pain conditions. The impact of patient education and SC on pain and other common HNC symptoms need further clarification. The aims of this thesis were: to describe experiences and perceptions of pain in patients with HNC shortly after RT to describe how relatives perceived the patient’s situation, especially concerning pain, and how they experienced their own situation to identify factors that impact HR-QoL during early RT to develop effective pain management strategies, maintain activities of daily living, and promote HR-QoL in patients with HNC undergoing RT using patient education and SC instruction. In paper I patients with HNC described existential pain – expressed as fear of death, meaninglessness and guilt – already during and shortly after RT. Physical pain, psychological distress and social withdrawal played a significant role. Patients with HNC who were treated with RT should also proactively be offered treatment for the various dimensions of pain. In paper II relatives described their mental stress in response to a challenging situation that required their active support to help ease the patient's difficult condition. The interviews with relatives also revealed a lack of personal knowledge and frustration over the inability to participate in patient care, as well as inadequate support from the healthcare system. Early interventions from the healthcare system on behalf of the relatives may be necessary to meet these needs. In Paper III regression models revealed that pain intensity and symptoms of depression adversely affected HR-QoL in patients with HNC during early RT. Customized prehabilitation programs aimed at preventing pain and symptoms of depression could help preserve good HR-QoL. Paper IV assessed individual patient education and SC initiatives that resulted in a tendency for lower pain intensity during a portion of RT. One way to potentially enhance the benefits of education and SC could be to improve for example patient motivation and self-efficacy, as well as to optimize supportive efforts from caregivers. In conclusion, by identifying factors that can impact HR-QoL and evaluating the effect of patient education and SC, this thesis contributes to knowledge on perceived pain and the patient’s situation during and shortly after RT in patients with HNC and their relatives. This thesis points to the need for evaluation and further development of patient education and effective SC strategies for pain in patients with HNC undergoing RT, as well as for development and evaluation of support strategies for patients with pain and their families during and after RT.