Good history-taking skills are the first step towards achieving a correct diagnosis of sexual dysfunction (SD). However, studies show most general practitioners (GPs) do not take the initiative to ask the patient about SD, and when diagnosing a condition, they tend to give preference to their own criteria over clinical guidelines. The aim of this study is to characterize GPs' attitudes towards taking sexual history, identifying its frequency and focus, and to describe GPs' diagnostics and therapeutic approaches including the use of clinical guidelines, exploring patients' and doctor-related differences. Cross-sectional study using confidential self-administrated questionnaires applied to GPs working in primary healthcare units in the Lisbon region. Data concerning GPs' consultation of guidelines, active exploration of SD in male and in female patients, and focus on sexual history taking was collected. Of the 50 participants (73.5% response rate), 15.5% actively ask their patients about SD. The main reasons for asking patients about their sexuality are diabetes (84.0%), prescription of medication with adverse effects on sexuality (78.0%), and family planning (72.0%), the latter being a significantly more frequent reason for GPs with 20 or less years of practice. Routine sexual history taking (22.0%) appears as one of the least mentioned motives. The percentage of appointments with active exploration of SD was positively associated with guidelines' consultation, as well as considering the specialty as a good source of information and having longer appointments when SD is mentioned. However, 76.0% report not having consulted any guidelines in the previous year. Lack of time (31.6%) and low accessibility (25.0%) were referred to as the main reasons for not consulting guidelines. Routine sexual history taking and consultation of guidelines about SD are not yet a generalized practice in primary care. Data should be interpreted with caution as they are self-reported. Further objective measurement such as direct observation or clinical files consultation should be implemented.