Given their ubiquitous progressive nature and unfavorable prognosis, interstitial lung diseases (ILD), especially such common variants as idiopathic pulmonary fibrosis (IPF) and hypersensitivity pneumonitis (HP), rightly attract considerable attention from clinicians and scientists worldwide. In recent years, the need for an in-depth study of the clinical and pathogenetic features of ILD, improvement of existing approaches and development of effective personalized approaches to the management of this category of patients, based on the most promising targets of action, among which genetic and epigenetic variants are increasingly being considered, has become increasingly important. The authors conducted a non-systematic, descriptive review of the literature aimed at systematizing data on the main known genetic and epigenetic mechanisms involved in the pathogenesis and formation of specific clinical manifestations of IPF and HP. Mutations in genes encoding telomerase, synthesis of fibrogenesis factors, polymorphisms of mucin genes, lung surfactant are highlighted separately, and the main epigenetic changes involved in fibrogenesis processes are highlighted separately. Prospects of genetic and epigenetic studies for new pharmacological approaches and monitoring the effect of already available treatment methods are analyzed. The search for literature sources was conducted in the Scopus, Web of Science, MedLine, The Cochrane Library, EMBASE, Global Health, CyberLeninka, and RSCI databases by the keywords “interstitial lung diseases”, “idiopathic pulmonary fibrosis”, “hypersensitivity pneumonitis”, “familial pulmonary fibrosis”, “genetic”, “epigenetic”, “precision diagnostics”, “therapy” with a search depth of 20 years.