Objective: To investigate the prevalence of palliative sedation use and related factors. Methods: An observational study based on data collected via electronic questionnaire comprising 23 close-ended questions and sent to physicians living and working in the state of São Paulo. Demographic data, prevalence and frequency of palliative sedation use, participant's familiarity with the practice and related motivating factors were analyzed. In order to minimize memory bias, questions addressing use frequency and motivating factors were limited to the last year prior to survey completion date. Descriptive statistics were used to summarize data. Results: In total, 20,168 e-mails were sent and 324 valid answers obtained, resulting in 2% adherence. The overall prevalence of palliative sedation use over the course of professional practice was 68%. However, only 48% of respondents reported having used palliative sedation during the last year, primarily to relieve pain (35%). The frequency of use ranged from one to six times (66%) during the study period and the main reason for not using was the lack of eligible patients (64%). Approximately 83% of physicians felt comfortable using palliative sedation but only 26% reported having specific academic training in this field. Conclusion: The prevalence of palliative sedation use is high, the primary indication being pain relief. However, frequency of use is low due to lack of eligible patients.