Introduction: Glaucoma is a chronic progressive ocular disorder characterized by optic nerve damage associated with visual field loss, ultimately culminating to blindness. Topical anti-glaucoma medications are used commonly for the management of glaucoma. But the long term use of same may lead to various ocular surface disorders (OSD). Usually the preservatives added in these medications are responsible for OSDs. Aim: To evaluate the prevalence of OSD in patients treated with topical anti-glaucoma medications and to analyse the relationship of benzalkonium chloride (BAK) concentration with duration of topical medication and number of drug used as topical medication in glaucoma patients. Materials and Methods: The present prospective study was conducted on 38 patients (76 eyes) of glaucoma attending glaucoma clinic of a tertiary care health centre after taking informed consent from patients and approval from Institutional Ethics Committee. All patients with primary open angle glaucoma, primary angle closure glaucoma and ocular hypertension aged 18 years or above were included in the study. All the enrolled patients were asked to complete the Ocular surface disease index (OSDI) questionnaire; after that they all undergone Schirmer’s 1 test and Tear Breakup Time (TBUT) for detection of OSDs. Results: Mild to moderate prevalence of OSD was reported in 10 (26.3%) patients by OSDI questionnaire. 13 (34.2%) patients showed mild to moderate symptoms of OSD by Schirmer’s 1 test while 9 (23.7%) patients showed severe symptoms. Results by TBUT test showed mild to moderate symptoms of dry eye in 19 (50%) patients while 5 (13.2%) patients showed severe symptoms. Longer duration of treatment (more than one year) was associated with more symptoms of OSDs. Conclusion: Longer duration and increased number of anti-glaucoma medication lead to more subjective symptoms of OSD as calculated by OSDI questionnaire, Schirmer’s test and TBUT test. Increased concentration of BAK in different anti-glaucoma medication was responsible for more symptoms of OSD.