RESUMEN
To standardise sociomedical expertising procedures in surgery of the breast a project team of medical advisors of the Medical Advisory and Expertising Service North Rhine worked out a manual. A form was created for sociomedical pre-advice occasions. Detail parameters for examination (time needed and advisor selection) were fixed in consent. Checklists were worked out, which may be admitted to quality assurance procedures. The manual "Medical opinion for surgery of the breast" has been implemented and is applied in the Medical Advisory and Expertising Service North Rhine since January 1999. In the sense of teamwork participation those who were involved as team-workers became participants in decision-making. The manual "Medical opinion for surgery of the breast" may be seen as an example of quality assurance and participation in socio-medical opinion procedures. The influence of this manual on the formal quality of medical opinion will be checked.