<p>This paper reports on the experiences of two nurse researchers sampling from clinical and research databases for the purpose of research. The authors focus on their practical experiences of using databases to identify potential participants for research, and explore the implications for conduct of research and potential impact on response rates and analysis of non-response bias. The Records Management: NHS Code of Practice (Department of Health (DH) 2006) and its implications for the creation and maintenance of records, including databases, are covered comprehensively in another article by Reay and Firth (2008).</p>