To perform an integrative review of the literature on the effectiveness of intravascular laser irradiation of blood (ILIB) as an adjunct therapy in the treatment of chronic systemic diseases. This is an integrative literature review that included non-randomized and randomized controlled clinical trials that specifically evaluated the therapeutic effect of ILIB on chronic systemic diseases, without restriction of time, and written in English. The Medical Publications (PubMed)/MEDLINE database was used. MeSH (Medical Subject Headings) was used to select search descriptors with the Boolean operators “AND/OR.” After applying the inclusion and exclusion criteria, 13 articles were selected. Coronary diseases were the most prevalent, followed by type 2 diabetes mellitus, with the coronary artery being the most widely used access route for ILIB application. Despite the varied parameters and protocols for using this kind of therapy, all studies have shown satisfactory results in the patients’ clinical condition. ILIB proved to be effective in all organic systems, showing some positive result. However, studies on the effect of this therapy on various diseases are still scarce in the literature, and there is a need for more well-designed clinical trials to better understand the role of ILIB in various systemic diseases.