Aim: To determine efficiency of training on reproductive health provided by peer trainers to the first-year nursing students. Method: This quasi-experimental study was designed as pretest-posttest in single group. In the study, the training of reproductive health was provided to 58 students studying at nursing department of a university by peer trainers. The data were collected by using a questionnaire and the Reproductive Health Scale before and six weeks after the training. The data were analyzed by using Chi-Square and Wilcoxon signed rank test in SPSS 16.00 program. Results: Among the students having an average age of 19.65±3.61, the rate for describing reproductive health correctly increased from 20.7% to 84.5%(p=0.000) and the rate of being aware that condom is the safest method for protecting from sexually transmitted infections increased form 31.0% to 60.3% (p=0.004) in posttest compared to pretest. Significant increases were determined on favor of posttest in terms of the rate of describing the risks brought by random sexual life and the rate of knowing names, symptoms, and transmission ways of sexually transmitted infections. An increase was observed in all of known family planning methods and in overall and all subscale mean scores of the scale used in the study in posttest compared to pretest. However, only some of them were found to be statistically significant. Conclusion: While peer education had a limited effect on teaching family planning methods to nursing students, it was effective for teaching the definition of reproductive health, risks of random sexual life, and names, indications, and transmission ways of sexually transmitted infections, and improving the behaviors of reproductive health.