Veterans with posttraumatic stress disorder (PTSD) symptoms frequently present to primary care providers (PCPs) and are reluctant to seek out or accept referrals to specialty mental health care. Most PCPs have not been trained to assess for and manage symptoms of PTSD. Web-based programs are increasingly used for medical education, but there are no published evaluations of online PTSD trainings for PCPs. We developed a 70-min Web-based training that focused on military-related PTSD for PCPs practicing in Veterans Affairs (VA) hospitals, but was applicable to PCPs treating veterans and other trauma-exposed patients outside VA settings. The training consisted of four modules: (1) Detection and Assessment; (2) Comorbid Conditions and Related Problems; (3) Pharmacological Interventions; and (4) Psychotherapeutic Interventions. Clinical vignettes dramatized key training concepts. Seventy-three PCPs completed the training and assessments pre- and posttraining and 30 days later. Paired t tests compared change in PTSD-related knowledge and comfort with PTSD-related skills, and qualitative methods were used to summarize participant feedback. After the training, mean knowledge score improved from 46% to 75% items correct, with sustained improvement at 30 days. Thirty days posttraining, PCPs reported significantly greater comfort regarding PTSD-related skills assessed; 47% reported using training content in their clinical practice. Qualitatively, PCPs appreciated the flexibility of asynchronous, self-paced online modules, but suggested more interactive content. Given the numerous barriers to specialty mental health treatment, coupled with a preference among veterans with PTSD for accessing treatment through primary care, improving PTSD competency among PCPs may help better serve veterans’ mental health needs.