OBJECTIVES: The objective of this study was to investigate treatment patterns and medication adherence of glaucoma. Also, it aimed to identify the key factors associated with non-adherence. METHODS: It was a cross-sectional, multicenter and observational study where glaucoma outpatients with less than two years of eye-drop use were recruited at 15 eye clinics from March to November 2013. Data was collected through a self-administered questionnaire and medical chart review. Medication adherence was evaluated using a patient self-report on pill count and defined as patients administering the drug for ≥80% of prescribed days. The medication adherence rate was calculated dividing the actual number of administration from the total prescribed number of administration for 7 days. In addition, patients whose self-reported prescription was different from the total number of prescribed daily doses by physicians were considered as non-adherence. RESULTS: