Malignant tumours of the salivary glands in children are extremely rare. We present here a 12-year-old girl initially diagnosed as pleomorphic adenoma on fine needle aspiration biopsy, and adenoid cystic carcinoma (ACC) after the lesion was excised and examined by histopathology. A wide resection of the lesion and bilateral supraomyohyoid neck dissection was performed. To our knowledge this is one of the youngest patients with ACC of the minor salivary glands. Due to its benign histological appearance, the biological agressiveness of ACC is usually underestimated. Although fine needle aspiration cytology (FNAC) is very valuable in diagnosis, cytological variations of pleomorphic adenoma must be considered. ACC of the tongue in a young age group should be treated with wide resection and selective neck dissection if the tumour is localized in places where the risk of metastasis is increased and if there is a clinically palpable lymph node. In such cases the clinician should not avoid radical operations even in a young patient.