The most frequent chronic respiratory problems in childhood are asthma and cystic fibrosis (CF). The purpose of this paper is to review basic knowledge and recent advances in oral health and associated dental morbidities in children with asthma and CF. This review considered clinical trials and systematic reviews related to oral health in children with CRD. An online base Medline was searched to determine relevant papers, using the combination of the following terms: “asthma”, “cystic fibrosis”, “caries”, “dental erosion”, and “oral health”. Oral health problems in children with chronic respiratory diseases (CRD) may be influenced by natural course of the disease, pharmacotherapy (inhalation therapy with bronchodilators and inhaled corticosteroids in asthmatic patients, systemic antibiotics and pancreatic enzyme replacement therapy in CF patients), medication administration technique and nutritional habits. Children with CRD may have higher prevalence of oral diseases. Patients and their parents, but also general paediatricians and pulmonologists, should be aware of importance of good oral health. Dental practitioners should be more informed about risk factors and specificities of oral health in these patients. Preventive measures, early diagnosis and effective treatment strategies in children with CRD can reduce occurrence of oral diseases and improve patient’s quality of life.