Unguarded severe tricuspid regurgitation caused by rupture of papillary muscle or chordae tendineae is rare but fatal in neonates. The experience in the management of these patients is still limited. A newborn presenting severe cyanosis after delivery was diagnosed with severe tricuspid regurgitation secondary to rupture of chordae tendineae by echocardiography (Echo), then treated by surgical reconstruction of chordae/papillary muscle connection without artificial materials. A takeaway lesson from this case is that Echo is an important method to diagnose a rupture of chordae tendineae or papillary muscle and that prompt diagnosis and timely surgery can be life-saving.