Seventy-one patients presenting with acute herpes zoster ophthalmicus were followed up for six months for a prospective analysis of the natural history of the disease. Acute and chronic ocular complications, nasociliary nerve involvement, age, sex, rash, and pain were assessed, and the results are presented. Acute pain was measured by a visual analogue scale. Postherpetic neuralgia (PHN) was more likely in patients over 80 and in those who scored their pain highly at presentation. Duration of rash was longer in patients who developed PHN. No other associations between the parameters studied were found. Nasociliary nerve involvement was associated with subsequent ocular disease.