The questionnaire is probably the most common form of data collection tool used in nursing research. There is a misconception that anyone with a clear grasp of English and a modicum of common sense can design an effective questionnaire. Contrary to such common belief, this article will demonstrate that questionnaire design is a complex and time consuming process, but a necessary labour to ensure valid and reliable data is collected. In addition, meticulous construction is more likely to yield data that can be utilized in the pursuit of objective, quantitative and generalizable truths, upon which practice and policy decisions can be formulated. This article examines a myriad of fundamental issues surrounding questionnaire design, which encompass question wording, question order, presentation, administration and data collection, amongst other issues.