Trilateral retinoblastoma (TRb) is a rare combination of unilateral or bilateral retinoblastoma with an ectopic midline intracranial neuroblastic neoplasm (primitive neuroectodermal tumour) usually in the area of pineal gland or sellar region. TRb can occur with both familial and sporadic forms of retinoblastoma. An occurrence of this rare tumour in a 12-year-old boy who had unilateral retinoblastoma in association with ectopic suprasellar primitive neuroectodermal tumour (PNET) is reported here. To the best of our knowledge, this is the first case report in Pakistan on TRb with suprasellar mass.