Purpose: The aim of the current study was to determine how carer needs changed longitudinally and understand associations between unmet needs and distress. Methods: Family carers of patients with high-grade glioma (HGG) were recruited. Carers completed questionnaires during patients’ chemoradiotherapy (T1), 3 months (T2) and 6 months (T3) including the following: the Distress Thermometer, the General Health Questionnaire-12, the Partner and Carer Supportive Care (PCS) Needs Scale and its supplement the Access to Services Needs Scale and the Brain Tumour Specific Supportive Care Needs Scale. Linear latent growth models were applied. Results: The time 1 questionnaire was completed by 118 carers; 70 carers provided responses at time 3. While the mean numbers of elevated (moderate to high) needs remained stable over time, the specific needs changed. The most frequently reported PCS needs included the impact of caring on the carer’s working life or usual activities, finding more accessible parking, making life decisions in the context of uncertainty, reducing stress in the patient’s life and understanding the patient’s experience. The most frequently reported need unique to carers of a brain tumour patient was for information on adjusting to cognitive changes in the patient. Other prominent needs included managing difficult aspects of the patient’s behaviour and adjusting to changes in the patient’s personality, both of which increased over time. Higher numbers of unmet needs were associated cross-sectionally with higher distress levels. Conclusion: Carers of people with HGG remain highly distressed and their needs evolve over time, indicating a requirement for ongoing evaluation of unmet needs and interventions to address carer psychological morbidities.