Background <p>This systematic review aimed to investigate the effect of different blood decontamination methods on dentin bond strength across various adhesive systems.</p> Methods <p>This systematic review was conducted in accordance with PRISMA 2020 guidelines and registered in PROSPERO (CRD42022381287). A comprehensive electronic search of Medline/PubMed, Web of Science, Scopus, and Embase was performed up to February 26, 2026. In vitro studies evaluating the effect of blood decontamination methods on dentin bond strength were included. Risk of bias was assessed using the QUIN tool. A qualitative synthesis was conducted. by stratifying the results based on decontamination method and adhesive systems.</p> Results <p>Fifteen in vitro studies comprising 1,015 teeth met the inclusion criteria. Eleven studies had low risk of bias, while four demonstrated a moderate risk of bias. Blood contamination consistently reduces dentin bond strength across adhesive systems with the most severe effects occurring when contamination happens after polymerization. Some approaches, such as adhesive reapplication and phosphoric acid re-etching in etch-and-rinse systems, as well as sodium hypochlorite combined with antioxidants, show the most promising results.</p> Conclusion <p>Blood contamination reduces bond strength to dentin. Although various decontamination methods can partially improve bonding, full recovery to uncontaminated levels is not reliably achieved. The effectiveness of decontamination strategies varied according to adhesive type, contamination timing (before or after adhesive curing), and decontamination protocol.</p>