Objective: To determine the aetiology of headache in patients seen for an ocular examination. Methods: This cross-sectional, descriptive study was conducted at Ophthalmology Department of Karachi Medical and Dental College, Abbasi Shaheed Hospital, Karachi, from January to December 2014, and comprised patients with headache. Patients were registered through non-probability consecutive sampling technique. A predesigned proforma was used to collect data. Complete ocular examination and investigations were conducted along with neuro-ophthalmological examination. Data analysis was done using SPSS 16. Results: Of the 379 patients, 225(59.4%) were female and 154(40.6%) were male. The mean age was 35.12 +/- 16.387 years (range: 6-75 years). Conditions associated with headache were divided as ocular, non-ocular and combined pathologies. Among ocular causes, asthenopia was amajor entity as 62(16.36%) asthenopic patients presented with refractive errors. These were followed by presbyopics who presented with complaint of headache 56(14.78%). The number of computer users with similar complaint was 18(4.76%). Among other ocular causes of headache, the number of patients with corneal ulcers was 22(5.80%), glaucoma 15(3.96%) and endophthalmitis 4(1.06%). Among the non-ocular causes were hypertension 59(15.57%), sinusitis 41(10.82%) and migraine 47(12.4%). Conclusion: The majority of patients had associate ocular causes such as refractive errors and anterior segment pathologies.