Over the past 200 years, there have been periodic shifts in the terminology used to describe what is still most commonly referred to in the medical world as 'mental retardation'. There are differing opinions about the acceptability of the term, but very little existing evidence on which clinicians can base their decisions regarding what terminology to use with patients and families, and with one another. The present survey of parents and professionals used questions based on paper-based clinical scenarios to survey each group's attitudes about terminology usage. The results of both the parent and professional surveys support a move away from the use of the term mental retardation. The majority of parents indicated that they would be upset if a physician used the term mental retardation. Some professionals reported being criticized for using the term. Teaching about terminology has been variable.