To describe the clinical and histopathological features of lymphomas involving the iris. Retrospective, descriptive study. Fourteen eyes of 13 patients. Review of medical records. Clinical and histopathological findings. Median patient age was 58 years (range, 25-76 years). Seven patients had known systemic lymphoma of which five were of large B-cell type. Symptoms included blurred vision (8/14), eye redness (3/14) and eye pain (2/14). Four eyes had secondary elevated intraocular pressure. Anterior segment findings included anterior chamber cells (14/14 eyes), keratic precipitates (11/14 eyes), congestion of conjunctival/episcleral blood vessels (9/14), hyphaema (7/14), conjunctival/anterior epibulbar lymphoma (6/14), tumour-induced pseudohypopyon (4/14) and corneal oedema (3/14). Of 12 eyes with adequate view of iris details, clinically detectable iris thickening or visible mass was noted in all (12/12). There was concomitant involvement of ciliary body (8/14), choroid (5/14) and orbit (2/14). All patients had biopsy of conjunctiva, episclera, iris or ciliary body, confirming the diagnosis of lymphoma. Histopathological or cytopathological evaluation of iris or ciliary body showed high-grade lymphoma in 9/11 eyes in which it was performed. Five patients did not have long-term follow up and, of the other eight patients, three died from complications of systemic lymphoma during follow up ranging from 1 to 44 months. Lymphomatous involvement of the iris should be considered in the differential diagnosis of corticosteroid-resistant uveitis in middle-aged and elderly patients. Iris lymphoma tends to be high grade and usually develops in patients with known aggressive systemic lymphoma. © 2012 The Authors. Clinical and Experimental Ophthalmology © 2012 Royal Australian and New Zealand College of Ophthalmologists.