Primary adrenal insufficiency is rare in childhood and adolescence. Is presented a case of a teenage boy, sixteen years old, admitted in the sequence of abdominal pain, asthenia, weight loss, nauseas, occasional vomiting, dizziness and hyponatremia/hyperkalemia, with a family history of tuberculosis that affected his father 15 years ago. In the clinical examination he had mucocutaneous hyperpigmentation, postural hypotension and emaciated appearance with no signs of dehydration. Analytical study confirmed the diagnosis of primary adrenal insufficiency. Imaging evaluation and tuberculin skin test and IGRA (interferon-gamma release assay) suggested a chronic process of mycobacterial origin. Diagnosis of adrenal insufficiency, although quite simple, is only possible if the physician keeps a high index of suspicion. Tuberculosis, a rare cause in developed countries, cannot be forgotten in the Portuguese population. 2016 Sociedade Portuguesa de Endocrinologia, Diabetes e Metabolismo. Published by Elsevier Espafia, S.L.U.