The wave of Good Clinical Practice (GCP) that swept Europe in the mid-eighties also hit Denmark. The influence from the USA was highly significant. However, the history of GCP in Denmark builds upon the ethical and scientific requirements for clinical trials of drugs which had developed over the preceding two decades. Furthermore, quality assurance of trials were already in progress. The Danish health authorities and the pharmaceutical industry were cooperating well in the evolution of GCP in Denmark. Parallelly, Denmark took an active part in the international harmonisation of the various GCP-guidelines within the Nordic countries, in the European Community, and world-wide through the development of the WHO- and the ICH-guidelines. In the work with these guidelines, several experts from a number of countries collaborated with Danish experts. Through this continuous interaction, Denmark profited from the tight connection with the circles and institutions where this development took place, both causing an increased awareness of GCP in Denmark, and an indisputable contribution from Danish participants to the international GCP-development. In 1987, an interdisciplinary Danish GCP Society was established. This has increased the understanding of GCP and, together with other activities, promoted the cooperation between the health authorities, the law-based ethics committee system, the sponsors, the investigators, and the Danish Data Protection Agency. The Society has arranged numerous courses and seminars, and held conferences and meetings in order to inform about GCP. The Danish GCP Society seems internationally to be rather unique in its scope and work. It is concluded that Denmark is well prepared for the coming regulations of trials on medicinal products proposed by the EU.