PURPOSE: This study was done to develop a Web-based preconception health promotion program to improve preconception health promotion awareness, perceived benefits, perceived self-efficacy and health behavior, and to reduce perceived barriers in couples about to be married. METHODS: Participants were assigned to the experimental group (n=26 couples) or control group (n=25 couples). This program was comprised of a six hour Web-based lecture series which was given to the experimental group over a four week period. RESULTS: Results for the two groups showed: 1) a significant difference in preconception health promotion awareness in men (self-perception: z=-3.62, p <.001 content: F=18.49, p <.001) and in women (self-perception: z=-2.89, p =.004 content F=36.93, p <.001), 2) a significant difference in perceived benefits in men (z=-3.09, p =.002), and in women (F=6.38, p =.004), 3) a significant difference in perceived barriers in men (F=3.64, p =.030), and in women (F=11.36, p <.001), 4) a significant difference in perceived self-efficacy in men (F=12.16, p <.001), but no significant difference in women (F=1.93, p =.166), 5) a significant difference in health promoting behavior in men (F=16.31, p <.001), and in women (F=10.99, p =.001). CONCLUSION: The results of this study show that the program is an effective nursing intervention in couples about to be married. Therefore, this program can be useful in encouraging health-promoting behavior for couples about to be married.