Aims and objectives To investigate whether a symposium aimed at healthcare professionals in the uro-oncological field changes knowledge, competence and general practice regarding sexual dysfunction after prostate cancer treatment. Background Sexual dysfunction is not frequently discussed by healthcare professionals; lack of knowledge and training are two of the most often reported barriers. Provision of additional training could improve knowledge, competence and general practice of healthcare professionals. Design Two questionnaires were used in this pre–post study to determine knowledge, competence and general practice at the time of the symposium and six months afterwards. Methods In order to perform repeated measures to analyse alterations among participating healthcare professionals (n = 55), the McNemar's test was used. A STROBE checklist was completed. Results Seventy-three per cent (n = 40) stated that not enough attention was paid to prostate cancer-related sexual dysfunction during their education. Nurses felt significantly less competent in discussing sexual function, advising on sexual dysfunction and actively inquiring sexual complaints compared to other healthcare professionals. After the symposium, sexual dysfunction was significantly more often discussed. No significant effects were found on knowledge on sexual dysfunction, knowledge on treatment of sexual dysfunction, competence in discussing sexual function, advising on sexual dysfunction, actively inquiring sexual complaints and rate of referral. Tools needed to address sexual dysfunction concerned written information materials (75.5%) and a website containing adequate information (56.6%). Conclusions The symposium had no significant influence on knowledge, competence and rate of referral in men with sexual dysfunction after prostate cancer treatment. However, sexual dysfunction was more frequently discussed after the symposium, so increase of awareness of consequences of prostate cancer treatment was achieved.