On-line therapy offers many advantages over face-to-face settings. Interapy includes psycho-education, screening, effect measures and protocol-driven treatment via the Internet for clients. The present paper reports the results of a controlled trial on the Interapy treatment of posttraumatic stress and grief in students, gaining course credits. The participants in the experimental condition (n = 13) improved significantly than the participants in the waiting-list control condition (n = 12), on trauma-related symptoms and general psychopathology. The effect sizes were large. Eighty percent of the treated participants showed clinically significant improvement after treatment. The possibilities for future research with Interapy, including studies into moderating variables, are discussed.