Rationale:Tuberculosis is an entity that usually affects the lungs, although extrapulmonary sites can also be involved. Tonsils are rarely affected, especially in the absence of pulmonary disease, primary tonsillar tuberculosis being a diagnostic challenge for the clinician.Patient concerns:We present the case of a 14-year-old female teenager, presented to our Pediatric Service with a 14-day history of dysphagia, odynophagia and left reflex otalgia associated with a 5 kg weight loss. Clinical examination revealed mild pharyngeal erythema, marked enlargement of the left tonsil infiltrating the lateral pharyngeal wall and the uvula and painful, mobile, nonadherent to deep bilateral latero-cervical adenopathy.Diagnosis:Positive interferon-gamma release assay (QuantiFERON-TB gold). Mantoux test reading was 16 mm.Interventions:During hospitalization, the patient received Clindamycin and Gentamicin for 3 days i.v., with discrete relief of symptoms and inflammatory markers. On the 4th day of hospitalization, treatment with Imipenem/Cilastin is started for 7 days in micro-perfusion, with tonsil hypertrophy decrease in size and favorable clinical evolution.Outcome:Tonsil hypertrophy decreased in size and patient had a favorable clinical evolution. At discharge, the patient was given a 6-month course of anti-tuberculous drug.Lessons:The particularity of this case is represented by the rarity of primary tuberculosis of tonsils in children, with unilateral involvement, displaying at the same time a common issue encountered in the current practice: the limitations and the difficult course of setting the diagnosis due to the involvement of relatives in the medical act.