To review the current approach of paediatric surgeons to the exclusion of androgen insensitivity syndrome (CAIS) in girls with inguinal hernias (IH), a questionnaire was sent to all specialist paediatric surgeons in the United Kingdom and Ireland asking if they exclude CAIS, how they exclude it, and what they say to parents preoperatively. In all, 32 surgeons responded (29%); 41% made no attempt to exclude CAIS because they thought the incidence was too low to justify exclusion; 19(59%) excluded CAIS at the time of surgery by assessment of the internal genitalia. Only 1 performed karyotyping primarily, and then only for bilateral IH. Although most would proceed to karyotyping if the primary assessment suggested CAIS, some would not. Of those who exclude CAIS, only 1 mentions CAIS preoperatively, 6 others mention gonadal inspection, and 12/19 (63%) make no comment. Thirty-one surgeons agreed to take part in a prospective study to define the incidence of CAIS in girls with IH. It is concluded that surgeons who exclude CAIS in girls with IH adopt different assessment methods, some of which may be unreliable. However, many do not attempt to exclude CAIS, believing the incidence to be too low. As the health and medicolegal consequences of failing to exclude CAIS may be considerable, surgeons should consider changing their practice. A prospective study should be undertaken to determine the incidence of CAIS in girls with IH.