Data are presented from two surveys where a 26-item questionnaire was used to measure patients' attitudes to diagnostic computers and to medical computers in general. The first group of respondents were 229 patients who had been given outpatient appointments at a hospital general medical clinic specializing in gastrointestinal problems, where some had experienced a diagnostic computer in use. The second group of respondents were 416 patients attending a group general practice where there was no computer. Patients who had experience of the diagnostic computer or a personal computer had more favourable attitudes to computers in medicine as did younger people and males. The two samples of patients showed broadly similar attitudes, and a notable finding was that over half of each group believed that, with a computer around, the personal touch of the doctor would be lost.