[Abstract] Secondary analysis of data from a survey among primary care physicians and from another survey among the general population provides information on the extent to which sexuality and HIV prevention are discussed in Swiss medical offices. Data on physicians show that they do not discuss sexual life issues routinely. When a sexual history is taken, questions are mainly asked about protection, and much less about the patient's sexual orientation and sexual practices. Regarding HIV risk assessment, physicians focus on patients considered at higher risk (drug users, men who have sex with men), and less on patients in more 'neutral' situations, such as during check-ups, with young adults, with new patients or with migrants. Patients' reported experiences are rather different: few people report having discussed HIV after a consultation with their doctor. Paying insufficient attention to sexuality impedes primary care physicians in their attempts to obtain necessary information to counsel and inform their patients, to help them if faced with difficulties or to detect certain pathologies. Medical training on three levels is needed to increase primary care physicians' skills in dealing with their patients' sexual issues: knowledge (for example, on the frequency of sexual problems, on STIs), skill (how to take a sexual history) and presence (talking with ease about sexuality). [Authors]