Extranodal thyroid lymphomatous involvement is rare in childhood. We report here 2 children, 1 with vertical transmission-acquired human immunodeficiency virus (HIV), presenting with lymphomatous infiltration of the thyroid gland at diagnosis. One child had infra-clinical endocrine impairment and both responded well to chemotherapy. Although the cases are too scarce to be affirmative, thyroid gland involvement doesn't seem to alter the good prognosis of childhood Burkitt's lymphoma. The third child's cancer in frequency is Non-Hodgkin Lymphomas. Presenting as the initial AIDS event in 1 patient, this case report also highlights the need to systematically propose antiretroviral therapy in vertically HIV infected children.