BACKGROUND Health care professionals should prevent and relieve suffering in carers of patients with advanced cancer. Despite known positive effects of systematic carer support, carers still do not receive sufficient support. Carers have reported to be less satisfied with coordination of care and involvement of the family in treatment and care decisions than patients. In a rural district of Mid-Norway, cancer palliative care services across specialist and community care were developed. Participants' experiences and opinions were investigated as part of this development process. METHODS The aim of this qualitative study was to explore and describe health care professionals' experiences with carer support from their own perspective. Data were collected in focus groups. Purposeful sampling guided the inclusion. Six groups were formed with 21 professionals. The discussions were audio-recorded, transcribed, and analyzed using systematic text condensation. RESULTS In the analyzis of the focus group discussions, ten categories emerged from the exploration of health care professionals' carer support, assessment of needs, and factors hampering carer support: 1) dependent on profession, role, and context, 2) personal relationship, 3) personal skills and competence, 4) adjusted to the stage of the disease, 5) informal assessment of carers' needs, 6) lack of education 7) lack of systems for carer consultations, 8) lack of systems for documentation, 9) lack of systems for involving GPs, and 10) lack of systematic spiritual care. CONCLUSIONS Health care professionals built a personal relationship with the carers as early as possible, to facilitate carer support throughout the disease trajectory. Systematic carer support was hampered by lack of education and system insufficiencies. Organizational changes were needed, including 1) education in carer support, communication, and spiritual care, 2) use of standardized care pathways, including systematic carer needs assessment, 3) systematic involvement of general practitioners, and 4) a system for documentation of clinical work with carers.