Purpose: Adolescence is considered a period in which individuals are particularly at risk of negative consequences related to sexual health. Increased knowledge levels have traditionally been used as an indicator of the effectiveness of educational programs, but attitudes are not addressed and are a key element for the success of such programs. The aim of this study is to determine the level of knowledge and attitudes toward the use of contraceptive methods among nursing students. A multicenter cross-sectional study was carried out. In total, 2914 university students (aged 18–25 years) enrolled in the study. Participants completed two validated scales to measure knowledge level and attitudes toward contraceptive use. Nursing degree students who received training about contraceptives obtained a success rate of over 70%, compared to 15.3% among students who had not received such training (p < 0.001). The mean attitude score was 43.45 points (10–50), but there were no significant differences in terms of student training (p = 0.435), although they were significantly higher among students who used contraceptives at first or last sexual intercourse (p < 0.001). There was a significant weak correlation between the level of knowledge and attitudes toward the use of contraceptives. An adequate level of knowledge about sexuality and contraceptive methods does not correspond to positive attitudes toward their use, although having an excellent attitude toward contraceptive use is related to their use during youth and adolescence.