The new regulations on clinical trials with medicinal products for human use include rules for Good Clinical Practice (GCP) inspections. These rules pertain to such inspections as part of the surveillance program of the relevant state authorities, in preparation for a decision on the authorization of clinical trials by the federal authorities, and pre and post approval GCP-inspections as one tool of Good Regulatory Practice (GRP). The overall aim of such inspections is to verify compliance with the provisions on GCP and, thus, to ensure the protection of trial subjects, the credibility and reliability of clinical trial results, and the pro-active protection of patients. Since inspection results have to be acknowledged by other member states, there is an increasing importance for quality assurance and harmonization of inspection procedures. As in most cases a considerable number of sites are involved in the conduct of clinical trials in different member states, there is a need for coordination of GCP inspections between these states.