Ocular manifestations form a part of the spectrum of varied clinical presentations in leukemias. Most of the ophthalmic manifestations are related to central nervous system leukemia and bone marrow relapse. We report a case of acute unilateral hypopyon uveitis as an initial presenting feature of relapsing acute lymphoblastic leukemia (ALL) in a pediatric patient. Anterior chamber paracentesis was performed in a four-year-old male child presenting with unilateral treatment-resistant hypopyon after remission of ALL. Examination of aqueous humor aspirate revealed presence of malignant cells. Atypical hypopyon, even unilateral can be an indication of relapsing ALL in a child.