Clinical cases involving paracoccidioidomycosis in children, diagnosed in Mato Grosso State, in the central western region of Brazil, are rare despite the state being classified with a moderate to high incidence. We describe a clinical case of infant acute disseminated Paracoccidioidomycosis in Mato Grosso State, Brazil, highlighting the importance of early differential diagnosis from other severe pathologies, thus contributing to the survival of compromised patients. A 3 year-old male child, weighing 12.8 Kg, originating from Vila Rica, MT, Brazil. The patient presented intermittent 40 masculineC fever evolving over 40 days, dry cough and painless bilateral cervical adenomegaly, showing no signs of inflammation. This was associated with diarrhea, distension and important abdominal pain and weight loss. Diagnosis was achieved by visualization of Paracoccidioides brasiliensis yeasts in a direct mycological exam and posterior fungus isolation in culture medium. The patient evolved presenting good clinical response to antifungal treatment and progressive reduction of abdominal and cervical ganglions. To improve the prognosis of compromised patients it is essential that professionals realize a full clinical-laboratorial evaluation, including differential diagnoses for other severe pathologies, as early as possible. The degree and intensity of paracoccidioidomycosis compromise are determining factors for defining the most efficient treatment.