Accurate pain assessment is considered essential for effective management of cancer pain. The aim of this study was to evaluate the compliance of hospitalized patients with chronic cancer pain, referred to an inpatient palliative care consultation service, with self-assessment of pain intensity by means of a daily pain form. The form was distributed daily by the pain consult nurse and required three daily pain intensity measurements on 0 to 10 numerical scales, separately for pain at rest and pain on movement. Of 174 consecutive patients, 106 (61%) participated in the study and were followed up for a median of 10.6 days (range 1-32 days). Compliance was defined as the number of assessment forms completed over the number of evaluation days available for each patient. Mean compliance was 58%. The main reasons for not completing the form were related to subjective psychological variables (44%), physical distress (26%), and absence of pain (16%). Lack of understanding of the method was reported as the main reason for non-compliance by only 1% of patients.