PurposeThis review aims to explore and summarise current knowledge of indocyanine green (ICG) fluorescence application in metabolic and bariatric surgery (MBS) and assess its potential in improving patient safety.MethodsThe review was prepared according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) recommendations. Evidence from PubMed, ScienceDirect and Ovid MEDLINE databases was independently screened in October 2022. The primary information and outcomes were the type of fluorescence application with potential patient benefit and the complication rate. The secondary outcomes consisted of the kind of dye, the application protocol, and the equipment used.ResultsThirteen publications were included, with six prospective observational studies, five case reports and two retrospective cohort studies and involved a total of 424 patients. The publications were categorized into four groups based on the method of fluorescence application. Sixty-six percent of the cases used fluorescence for LSG, 32.3% used it for RYGB, 1.2% for revisional surgery, 0.2% during removal of an adjustable gastric band, and 0.2% for LSG combined with Rossetti fundoplication. ICG was used on its own in the majority of studies, although in one case, it was used in combination with methylene blue. ICG administration protocols varied significantly. Complications occurred in three patients (0.71%): leaks were diagnosed in two cases, and one patient required a blood transfusion.ConclusionThe most popular type of use is intraoperative assessment of the blood supply. ICG application may reduce the risk of complications, with potential benefits in detecting ischemia and leaks, searching for bleeding in areas inaccessible to endoscopy, and non-invasive hepatopathy evaluation.