Purpose: The purpose of this study was to investigate the effects of a sexuality education coaching program given to elementary school students in terms of sex-related knowledge and attitude. Methods: The participants were elementary school students in S city (Experimental group=21, Control group=23). Data were collected and the program was conducted from Feb. 15 to Apr. 15, 2013. The experimental group of 21 elementary school students in the fifth and sixth grades who received the sexuality education coaching program, 10 sessions in the three weeks. The control group of 23 elementary school students in the fifth and sixth grades from another school received, 2 sessions in the three weeks on sexuality education including physiology and sexual abuse prevention. Data were analyzed using ${chi}^2$-test, independent t-test, repeated measures ANOVA, and utilized the SPSS program. Results: The experimental group showed significantly better sex-related knowledge and sex-related attitudes than the control group. Conclusion: Therefore, individualized approach with emphasis on the differences of their level of understanding and strengths should be considered in providing sexuality education coaching programs for elementary school students.