Sex education is not included in Turkey's national curriculum and is rarely referenced in school and university curricula. This is even true for those undertaking training in psychological counselling where the need may be great. Only a very few university schools of education offer an elective sex education course. A group of 64 guidance and psychological counselling students in Istanbul Maltepe University was formed and provided with a 13-week sex education course. Before and after this course, the Sexual Attitudes Scale (SAS) was used for data collection using a semi-experimental design. Significant differences were detected between pretest and post-test SAS scores and on all SAS subscales. Results show that comprehensive sex education is effective in positively changing the sexual attitudes of PC students, challenging homophobic responses and displacing patriarchal attitudes. Based on these findings, the provision of sex education courses more generally in university schools of education is recommended, especially in conservative countries such as Turkey.