Body dysmorphic disorder (BDD) occurs in about 5% of patients seeking cosmetic surgery. Such patients are often dissatisfied with surgery or their symptoms of BDD are the same or worse after surgery. We report on a study that was designed to determine the frequency of BDD in patients requesting cosmetic rhinoplasty in the UK and to compare them with BDD patients in a psychiatric clinic. In the first stage of the study, we used a screening questionnaire for BDD and found that 20.7% of patients requesting rhinoplasty had a possible diagnosis of BDD. However, we believe that we identified a group of patients with sub-clinical or very mild BDD who are satisfied by cosmetic rhinoplasty. In the second stage of the study, we compared (a) patients without BDD who had a good outcome after cosmetic rhinoplasty with (b) BDD patients seen in a psychiatric clinic (who crave cosmetic rhinoplasty but for a variety of reasons do not obtain it). We found that BDD patients seen in a psychiatric clinic who desire cosmetic rhinoplasty are a quite distinct population from those obtaining routine rhinoplasty without symptoms of BDD. BDD patients are significantly younger, more depressed and anxious than this group, and are more preoccupied by their nose and check their nose more frequently. They are more likely to conduct "D.I.Y" surgery and have multiple concerns about their body. They are more likely to be significantly handicapped in their occupation, social life, and in intimate relationships and to avoid social situations because of their nose. They are therefore more likely to believe that dramatic changes would occur in their life after a rhinoplasty. This study provides some clues for surgeons who wish to identify patients with BDD who might have a poor prognosis in cosmetic rhinoplasty. Further research is required in the development of a screening questionnaire or interview for identifying patients with BDD seeking cosmetic surgery.