Frequent pain assessment by the use of pain diaries for the follow-up of pain treatment can facilitate the caregivers' work with pain control in home health care. The aim was to explore and describe professional caregivers' experiences of palliative home health-care patients' use of pain diaries and digital pen technology for frequent pain assessment. A system for the follow-up of pain treatment was implemented in routine care and evaluated by means of a qualitative content analysis. Three nurses, two physicians and one secretary were interviewed. Additional analysis data were collected from patients' medical records, and the system log. The caregivers showed a shifting outlook towards the pain-assessment method, an initial cautious outlook due to low expectations of the patients' abilities to use the pain assessment method. Despite this, the caregivers experienced positive outcomes in terms of an increased awareness of pain, and positive patient influences including increased participation in their care, increased security, and improved changes in pain treatment as a response to reported pain assessments. Pain assessment by the use of pain diaries and digital pen technology has positive influences on palliative home-care patients and supports the caregivers' focus on the pain.