Tonsil malignancy is uncommon in children. Tonsillar asymmetry is usually secondary to a benign process, either inflammatory conditions, differences in the tonsillar fossa depth or anterior pillar asymmetry. However, it may indicate a serious underlying disorder such as lymphoma. Lymphoma is the most common childhood malignancy in the head and neck. Approximately, 15% of the cases affect the Waldeyer's ring. The most common clinical manifestations of palatine tonsils lymphoma are unilateral tonsillar hypertrophy, alteration in the appearance of the mucosa and ipsilateral cervical lymphadenopathy. Early diagnosis and appropriate treatment are of great importance in the prognosis. We present a case of palatine tonsil lymphoma in a child with tonsillar asymmetry and we emphasize the importance of the examination of the oral cavity and the neck to identify suspicious alterations compatible with tonsillar lymphoma.