Cardiovascular pathology is a leading cause of morbidity and mortality. An important task of modern cardiology is the search and study of new biological markers. Scientists’ interest is actively focused on the study of interleukin-38. Interleukin-38 is an anti-inflammatory cytokine and a member of the interleukin-1 family. This study aimed to analyze literature sources devoted to the study of interleukin-38 as a cardiovascular biological marker. Literature sources, including all relevant publications in PubMed (MEDLINE), RSCI, Google Scholar, and Science Direct, were analyzed. The search depth was 9 years. Interleukin-38 is found in the skin, heart, placenta, fetal liver, spleen, thymus, and activated B cells of the tonsils. Interleukin-38 protein is detected in human plasma, serum, and cell cultures by enzyme-linked immunosorbent assay. Interleukin-38 regulates immune and inflammatory responses by binding to its receptors and activating downstream signals. Its deficiency is associated with increased systemic inflammation in aging, cardiovascular diseases, and metabolic diseases. Currently, not much clinical and experimental data have been accumulated regarding the effect of interleukin-38 on the cardiovascular system; however, further studies are expected to demonstrate the possibility of its use as an additional laboratory tool for diagnosis and assessment of prognosis in patients with cardiac problems. Regulating the concentration and expression of interleukin-38 is a promising strategy for the treatment of cardiovascular diseases.