ENThe publication aims to define an Investigation Quality Management Framework which from the perspective of the quality of the expert witness opinion would be of help to the courts considering admissibility of the expert opinion as evidence in the court proceedings. Investigation Quality Management Framework is defined bearing in mind an investigation in the social science (economics, specifically calculation of damages) and could be further customized to the specific type of investigation. Investigation Quality Management Framework is based on the knowledge from the quality management (ISO 9001, EFQM Excellence model, ISQM1 etc.) as well as on the provisions of the International Standards on Auditing. Investigation Quality Management Framework could be applied by the experts with the selfassement purposes of the quality of the investigation, as well as evaluating the quality of the different kinds of the investigation reports performed by the supervision institutions. Investigation Quality Management Framework and its tools could be of help to the judges and parties to the dispute in assessing of expert opinion as evidence in the court proceedings.