This article reports two children with hereditary hemorrhagic telangiectasia (HHT). Patient 1 was a boy aged 12 years and was admitted due to intermittent cough and wheezing for more than 10 years. This boy and his mother and grandmother had a history of epistaxis. The boy had a history of the rupture of cerebral arteriovenous malformations. Gene detection showed a heterozygous mutation, c.277C>T(p.Arg93*), in the ENG gene. Patient 2 was a girl aged 13 years and was admitted due to cyanosis of lips for more than 1 year. The girl had a history of recurrent epistaxis and the manifestations of severe decline in pulmonary diffuse function, pulmonary hypertension, dilation of blood vessels at the distal end of lungs, and small arteriovenous communications in both lungs. Children with HHT often lack typical respiratory symptoms, which may lead to missed diagnosis and misdiagnosis in the early stage. Pulmonary computed tomography or right cardiac acoustic contrast can help with the diagnosis of HHT, and gene detection can improve the early diagnostic rate of this disease.