To review the literature regarding internet-based treatment of eating disorders (ED). Relevant studies were identified by searching electronic databases (including Medline, Embase, PsycInfo, and Web of Science). Eligible studies evaluated an internet-based treatment for ED, or an ED treatment that included at least one internet-based component. Twenty-one studies were included. Methodological quality varied. Internet-based treatments were superior to waiting lists in reducing ED psychopathology, frequency of binge eating and purging, and in improving (ED-related) quality of life. Internet-based treatment was more effective for individuals with less comorbid psychopathology, binge eating as opposed to restrictive problems, and individuals with binge eating disorder as opposed to bulimia nervosa. Higher levels of compliance were related to more improvements in ED symptoms. Study dropout ranged from 5.3 to 76.8%. Inclusion of face-to-face assessments and therapist support seemed to enhance study compliance. Overall, the internet can be considered an acceptable vehicle for delivering ED treatment. Future research should determine the utility of internet-based treatment by comparing them to face-to-face treatment. Research should furthermore focus on unraveling predictors and mediators of treatment outcome, compliance, and dropout, respectively. Studies with good methodological quality are needed with reports according to CONSORT guidelines. Copyright © 2013 Wiley Periodicals, Inc., A Wiley Company.