BACKGROUND: Appropriate pain assessment is a necessary prerequisite for adequate pain control. A way to follow-up on the pain is to let patients use paper-based or electronic pain diaries. PURPOSE: The aim was to explore and describe palliative home care patients' experiences of assessing their pain by using a pain diary together with digital pen and mobile Internet technology. METHODS: A system for the follow-up of pain treatment was developed and evaluated by means of a qualitative cross-case content analysis. From December 2002 until September 2003 12 palliative patients, who initially assessed VAS pain>or=35 mm (VAS 0-100 mm), used the system. Patients reported their momentary pain intensity and the number of consumed extra doses of analgesics three times per day. Analysis data were collected from interviews with patients and spouses, questionnaires, medical records, and the system log. RESULTS: In spite of severe illness and difficulties in comprehending the technology and system intervention, patients found the pain diary and digital pen easy to use for pain assessment. Patients took a greater part in their own care and experienced an improved contact with their caregivers, which led to a sense of increased security. The medical records showed a quick response to variations in the patients' health status by means of changes in medical treatment. CONCLUSIONS: The pain assessment system for palliative patients using pain diaries together with digital pen and wireless Internet technology constitutes an effortless method and has positive influences on the care.