Aim To identify the relative incidence and profile of adverse drug reaction (ADR) to various topical ocular hypotensives in a hospital setting. Methods All the patients presenting in outpatients clinic and accident and emergency with an ADR to topical hypotensive agent from August 2000 to January 2001 were included in the study. Details regarding the type date of commencing the treatment, the date of developing ADR, time to resolution of the ADR were noted. Results Over the period of 6 months, 66 patients presented with 73 ADRs. Brimonidine was the most frequent offending agent. In total, 23 (34.8%) presented with ADR after being commenced on treatment for more than 12 months. In all, 16 (24%) patients had IOP421 on presentation, eight (12%) patients underwent filtration surgery following the development of ADR. Conclusion Adverse drug reaction to ocular hypotensive agents is not uncommon and can have a major impact on glaucoma management. Delayed presentation and association with raised intraocular pressure presentation emphasise the need for effective patient education to encourage prompt reporting of ADR.