||This study examined parent-rated effectiveness and acceptability of a Webbased bullying prevention and identification program for parents of fourth- and fifth grade students. Participants included 60 parents and their children in the fourth and fifth grades. Participants were randomly assigned either to a newsletter-only group (n = 30) or a Web-access group (n = 30). Parent attrition rates in both groups reached 40%. An independent samples t test was performed on each factor comparing the mean-rated factors of Effectiveness, Acceptability, and Time Efficiency reported by the Web-access group with ratings reported by the newsletter-only group. Results indicated significant differences between groups across each factor. The mean Factor 1 (Acceptability) score for the Web-access group yielded the following: M = 4.48, SD = .383, and the newsletter-only group yielded the following: M = 4.17, SD = .140, f(34) = 3.23, p < .01. The mean Factor 2 (Effectiveness) score for the Web-access group yielded the following: M = 4.39, SD = .273, and the newsletter-only group yielded the following: M = 4.15, SD = .159), r(34) = 3.22, p < .01. The mean Factor 3 (Time Efficiency) score for the Web-access group yielded the following: M = 4.50, SD = .156, and the newsletteronly group yielded the following: M = 4.23, SD = .233), f(34) = 4.09, p < .01. Secondary analyses were conducted for the Incidental Student-Learning Questionnaires completed by the children of the participants. An independent samples t test was performed comparing the mean of correct responses of the Web-access group (M = 12.75, SD = .887) with the newsletter-only group (M = 9.5, SD = 2.268). The alpha level was .05. This difference was found to be statistically significant, f(34) = 5.678, p < .01, and could not be explained by chance. An effect-size calculation resulted in a Cohen's d of 1.89, which is considered a large effect upon the correct responses between groups, even considering the small sample size of the study.