Sexual fears, sometimes in the form of phobias, lead to aversive or sexually avoidant behavior blocking sexual closeness and resulting in deep personal and interpersonal distress. OBJECTIVE: To determine the types of sexual fears and aversive behavior in young people of reproductive age (students) and their degree of markedness as to encourage a further implementation of prevention programs and interventions. MATERIALS AND METHODS: The study included 116 fifth-year medical students in Plovdiv Medical University. Of these, 55 men and 61 women were assessed with the Sexual Aversion Scale, a 30-item self-rating questionnaire. The Diagnostic and Statistical Manual of Mental Disorders criteria of sexual aversion were used. The statistical analyses used were descriptive statistics and independent samples t-test. RESULTS: Sexual fears and aversive or blocking behavior are mild to moderate, mean score of 1.54 ± 0.04, without statistically significant gender differences. Both sexes have established fear-related sexual aversive motives of sexual behavior related to the risk of unwanted pregnancy and HIV infection. Women have significantly higher average scores for the following statements: fear of sexual intercourse (1.61 vs 1.25), avoidance of situations in which they may be involved sexually (1.95 vs 1.51), avoidance of genital sexual contact (1.44 vs 1.16), fear of catching a sexually transmitted disease (2.46 vs 2.09 ), fear of pregnancy (2.61 vs 2.15) and concerns what other people think of them (2.34 vs 1.93 ). CONCLUSIONS: Sexual fears and aversive or blocking behavior were mild to moderate. In both sexes similar fears - aversive or blocking patterns of sexual behavior were found, mainly associated with the fear of unwanted pregnancy and the risk of HIV infection, more expressed in women.