A 6-year-old boy from Comilla, was admitted in Dhaka Medical College Hospital with exertional dyspnea, central cyanosis, clubbing and was finally diagnosed as pulmonary Arterio-Venous Malformation (PAVM) by bubble contrast echocardiography, and pulmonary CT angiography. As PAVM is rare in children, it is often not thought of in differential diagnoses and the diagnosis remains in disguise. In this report, we described the clinical presentation of 6-year-old child with PAVM and also how to investigate the case to get the diagnosis.