A national enquiry was developed by the Pain Control Department of the Dutch Society of Anesthesiology (NVA) in co-operation with the National Organisation for Quality Assurance in Hospitals (CBO). A questionnaire for retrospective collection of invasive pain control data was sent to all (147) Dutch hospitals as part of the "Quality Assurance of Anesthesiological Pain Control Study" which took place from 1991 to 1997. The questionnaire related to the organisation of pain departments, availability of personnel, material and space facilities, use of treatment protocols, type and number of procedures carried out in cancer and non-cancer pain management during a 1 year period (1990-1991). The response rate to the enquiry was 98 per cent; this high response rate was important to evaluate the status of anesthesiological pain control in The Netherlands. During the study period 92 per cent of the respondents carried out 9,700 invasive cancer pain procedures; 85 per cent of the respondents were active in the field of chronic non-cancer pain control and were responsible for approximately 63,000 procedures.