This report is a summary of a Nordic co-operative project called “The Nordic Adaptation ofClassification of Occupationally Related Disorders (diseases and symptoms) to ICD-10”,financed by the Nordic Council of Ministers (Nordisk Ministerråd) and completed 1996 to2000.The aim of the project was to provide a “Nordic list of occupational disorders” with advice onhow to code them in accordance with the WHO International Statistical Classification ofDiseases and Related Health Problems (ICD) version 10. Coding of occupational disorders isnot always self-evident within ICD-10. This holds especially true for central nervous systemdisorders caused by occupational exposure and for some groups of not well-specifiedconditions, which in the Nordic countries are claimed, but not yet proven, to be caused byoccupational exposures. By giving advise on how to “modify and adapt” these conditions tothe ICD-10 system, we hope – if the advises are accepted – to facilitate later comparisons ofNordic data on occupational disorders.We also had a hope to be able to mark out disorders from occupational and environmentalexposures, to bring attention to the potential for their prevention, within the ICD-10. This canonly be done indirectly by adding the codes for occupational (Y96) or environmental (Y97)exposure to the codes for disorders. This can be done within the ICD-10, but we havediscovered that this possibility can be hampered by the design of local hospitals’ ICD-10registration systems, which may not allow the possibility to add other codes to the codes fordisorders.In addition the ICD-10 codes for exposure (chapter T) are insufficient for coding forexposures in the Nordic occupational- and environmental clinics. Thus a satisfactory codingsystem for exposures must be created outside the frames of ICD-10.