BACKGROUND: It is estimated that about half of cancer patients use at least one form of complementary and alternative medicines (CAM) in their life but there is a strong reticence of patients in talking about CAM with their oncologist. Primary aim of this study was to inform patients about CAM, focusing on their supposed benefits, toxicities and interactions with conventional therapeutic agents. The study also explored patients' perception about CAM and ascertained the level of CAM use among cancer patients of an Italian academic hospital. METHODS: From April 2016 to April 2017, the observational pilot trial "CAMEO-PRO" prospectively enrolled 239 cancer patients that were invited to attend a tutorial about CAM at the Department of oncology, University Hospital of Udine, Italy. Before and after the informative session, patients were asked to fill a questionnaire reporting their knowledge and opinion about CAM. RESULTS: Overall, 163 (70%) women and 70 (30%) men were enrolled. Median age was 61 years. At study entry, 168 (72%) patients declared they had never been interested in this topic previously; 24 patients (11%) revealed the use of a type of alternative therapy and 58 (28%) revealed the use of complementary therapy. In total, 139 (55.2%) patients attended the informative session. Bowker's test of symmetry demonstrated statistically significant opinion's change after the session on 9 out of 14 explored items. CONCLUSIONS: Informative sessions seem to have a relevant impact on patients' perceptions and opinions about CAM.