The increased prevalence rate of autism has immense implications for speech language pathologists (SLPs) who are directly involved in the education and service delivery for students with autism. However, few studies have documented the effectiveness of the knowledge and confidence of SLPs regarding autism. The purpose of this study was to measure the knowledge and confidence of SLPs regarding autism and the extent to which their educational and professional training prepared them to work effectively with this population. An online survey was administered to and returned by 336 SLPs nation-wide. Two multiple linear regressions were conducted to determine the variables that explained overall knowledge and confidence. The number of students with autism on one's caseload explained most of the variance. Independent sample t-test results depicted knowledge and confidence scores of SLPs who were behaviorally trained versus those who were not behaviorally trained. SLPs who were behaviorally trained had higher mean scores on measures of knowledge and confidence when compared to those without formal behavioral training. Finally, a bivariate correlation was conducted to explore the relationship between knowledge and confidence of SLPs, however, results were not statistically significant. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]