Aim of the study: Evaluation of the observance of the World Health Organization guidelines for cancer pain management is a prerequisite for further research into the effectiveness and acceptability of the guidelines. Methods: In a nationwide survey 172 physicians in pain management and oncological units documented transdermal therapy with fentanyl. From October 1996 to May 1997, 591 patients were included. A total of 148 patients had already received transdermal fentanyl before inclusion in the survey, and no data on previous analgesic management were available for 7 patients. For 436 patients analgesic therapy before initiation of transdermal fentanyl was evaluated. The last analgesic regimen documented by the treating physician was rated by three physicians from our pain clinic independently of each other. A rating system with four items (potency of analgesic according to the analgesic ladder of the WHO guidelines, prescription of a rescue medication, combination of nonopioids with opioids, inadequate combinations of analgesics) and a global rating (the analgesic regimen is considered adequate, sufficient or inadequate) was used. Results: Good agreement was reached for classification according to the analgesic ladder, prescription of rescue medication and for inadequate drug combinations. The ratings on combinations with nonopioids showed more differences. The scores for the global assessment showed a wide difference between raters, with agreement on the same score for only 36.2% (raters 1 and 3), 36.7% (raters 2 and 3) and 55.5% of the patients (raters 1 and 3). Conclusions: A global assessment score is not useful for evaluation of guideline acceptance. A more differentiated scoring system was developed for further studies that includes the analgesic ladder and other aspects of the WHO guidelines in a 10-point score.