Good Laboratory Practice regulations became effective on June 20, 1979. The regulations provide guidance for the proper conduct and reporting of nonclinical laboratory studies on articles regulated by the United States Food and Drug Administration. A fundamental requirement of the regulations is the establishment of a quality assurance unit within each research facility to ensure the utilization and maintenance of good laboratory practices. A second significant feature is the requirement for an archival unit responsible for maintaining all raw data, documentation, protocols, specimens, and final reports. Experience with the regulations has been mixed. The quality of reports has been upgraded dramatically. Protocols contain more information than ever, data recording is more extensive and more carefully executed, and reports are prepared more carefully and edited more thoroughly. Conversely, there is no real evidence that quality of science has been improved, and costs have increased markedly.