School-based sexuality education provides a means of disseminating valuable information about decision making and avoidance of risky behaviors that may result in an unplanned pregnancy or sexually transmitted infection; however, effective teacher training is required for efficacious sexuality education programs. The purpose of this paper is to describe changes in participants' perceptions and adoption of evidence-based sexuality education after attending a unique professional development opportunity for teachers of sexuality education using a Diffusion of Innovation Theory framework. Methods: A non-representative sample of 20 public school health education teachers (85% female) from across the state of Texas participated in the Sexuality Education Academy (SEA), and completed pre-, post-, and six-month follow-up Web-based surveys. Descriptive statistics and Wilcoxon signed-rank tests were used to measure change in perceptions and adoption of evidence-based sexuality education. Results: Statistically significant changes were found between pre- and post-test scores in "relative advantage," "compatibility," "complexity," and "observability." At six-month follow-up, participants indicated increased advocacy for and implementation of evidence-based sexuality education practices. Conclusions: Teacher training can improve sexuality education teachers' understanding, confidence and effectiveness in delivery of evidence-based sexuality education within school settings.