Objectives: The aim of this study was to identify guidelines and assessment tools used by health technology agencies for quality assurance of registries and investigate the current use of registry data by HTA organizations worldwide. Methods: As part of a European Network for Health Technology Assessment Joint Action work package, we undertook a literature search and sent a questionnaire to all partner organizations on the work package and all organizations listed in the International Society for Pharmaco-economics and Outcomes Research directory. Results: We identified thirteen relevant documents relating to quality assurance of registries. We received fifty-five responses from organizations representing twenty-one different countries, a response rate of 40.5 percent (43/110). Many agencies, particularly in Europe, are already drawing on a range of registries to provide data for their HTA. Less than half, however, use criteria or standards to assess the quality of registry data. Nearly all criteria or standards in use have been internally defined by organizations rather than referring to those produced by an external body. A comparison of internal and external standards identified consistency in several quality dimensions, which can be used as a starting point for the development of a standardized tool. Conclusion: The use of registry data is more prevalent than expected, strengthening the need for a standardized registry quality assessment tool. A user-friendly tool developed in conjunction with stakeholders will support the consistent application of approved quality standards, and reassure critics who have traditionally considered registry data to be unreliable.