Pulmonary arteriovenous malformation (PAVMs) in children are rare lesions characterized by abnormal low resistance vascular structures connecting a pulmonary artery to a pulmonary vein, resulting in an intrapulmonary right-to-left shunt. The insidious onset and variable signs and symptoms make diagnosis difficult, especially in children. PAVMs  can be single or multiple, congenital or acquired, and up to 47-80% of cases are associated with hereditary hemorrhagic telangiectasia (HHT).We present the  case of a 12-year-old female teenager referred to our center for epistaxis, headache, fatigue and weakness, with evidence of mild oxygen desaturation.  Bubble test showed a right-to-left shunt and pulmonary angio-CT confirmed the diagnosis. Percutaneous selective embolization was performed with full recovery of normal arterial oxygen saturation. When differentiating between mild oxygen desaturation and exercise intolerance in children and adolescents, physicians should be aware of the possibility of PAVMs as a cause.