Background: The Internet is a widely used resource for obtaining health information. Internet users are able to obtain anonymous information on diagnoses and treatment, seek confirmatory information, and are able to self-diagnose. We posted a self-report diagnostic screening questionnaire for DSM-IV anxiety and mood disorders (MACSCREEN) on our clinic website. Method: Three hundred and two individuals completed the MACSREEN. For those who qualified for a DSM-IV disorder, self-report symptom severity measures were completed for the specified disorder: Quick Inventory of Depressive Symptomatology, self-report, Social Phobia Inventory, GAD-7, Davidson Trauma Scale, Panic and Agoraphobia Scale, and Yale/Brown Obsessive Compulsive Scale, self-report. Cutoff scores for each self-report measure were used to evaluate clinically significant symptom severity. Respondents were also asked to complete a series of questions regarding their use of the Internet for health information. Results: The mean age of the MACSCREEN sample was 35.2 years (±13.9), where the majority (67.2%) were female. The most frequently diagnosed conditions were social phobia (51.0%), major depressive disorder (32.4%), and generalized anxiety disorder (25.5%). Sixty-five percent of the sample met criteria for at least one disorder. Most respondents reported completing the MACSCREEN, as they were concerned they had an anxiety problem (62.3%). The majority of respondents reported seeking health information concerning specific symptoms they were experiencing (54.6%) and were planning to use the information to seek further assessment (60.3%). Conclusion: Individuals with clinically significant disorder appear to be using the Internet to self-diagnose and seek additional information. Depression and Anxiety, 2010. © 2010 Wiley-Liss, Inc.