The study was carried out to determine the level of knowledge about sexual relations and AIDS in first grade medical students before and after education study at the University of Fırat, School of Medicine. Data was based on survey forms that were filled by a total of 101 students. The 66.3% of students were male and 33.7% were female. The mean age was 18,1±0,93 years and 58.4% was graduated from high school. The first three contraceptive methods before education were oral contraceptives (77.2%), condom (51.5%) and intrauterine device (24.8%). The most important knowledge source of students were TV, video or computer in 57.4%, newspaper and magazines in 55.4%, and books in 35.6%. 96.0% of students were aware of AIDS transmission. The first three answers about the tracts of transmission was as follows before and after education; sexully transmission (98.0%-100.0%), blood transfusion (94.1%-98.0%) and from mother to the baby (28.7%-89.1%). In a conclusion, students level of knowledge about sexual relations and AIDS was not sufficient, but improved with given education. It is thought that in every step of education these kind of knowledge must be given.