Purpose: This study was conducted to determine how frequently self-reported symptoms are captured as adverse drug events (ADEs) during chart abstraction. Method: We studied Ontario Cohort Study (OCS) participants attending the Toronto Hospital Immunodeficiency Clinic and compared OCS data on ADEs collected semi-annually through chart review and a self-administered questionnaire, completed on up to three occasions, which asked about the frequency, severity, and chronicity of symptoms including diarrhea, nausea, fatigue, and changes in body shape. Among 64 participants who completed the questionnaires, the median age was 42 years, the median time since HIV diagnosis was 9 years, 84% were male, 58% were men who had sex with men, 70% had viral load levels below 50 copies/mL, and the median CD4 was 422 cells/mm3. All patients were taking antiretroviral therapy. Results: The median (interquartile range) number of symptoms per participant reported on the questionnaire at the first visit was 3 (1-5). The most common symptoms reported by patients were diarrhea (58%), headache (59%), difficulty sleeping (52%), dry skin (53%), and changes in body shape (52%). The median number of ADEs during the study period per participant in OCS was 1 (0-2). Of 345 symptoms identified on the questionnaire, 16% were reported as ADEs in the OCS. Conclusion: Although some symptoms were correctly not classified as ADEs as they were not related to antiretroviral medication, others may have been missed due to incomplete reporting to the physician, incomplete physician recording, or errors in chart extraction.