To evaluate the effect of saliva and blood contamination on the shear bond strength of 6th, 7th, and 8th generation bonding agents.Seventy-two non-carious human mandibular molars were embedded in self-cure acrylic resin and flattened to expose dentin. The specimens were divided into three adhesive groups: Clearfil SE Protect (6th gen), Tokuyama Palfique Bond (7th gen), and G-Bond Premio (8th gen). Each group was further subdivided into three subgroups: control, contamination before curing, and contamination after curing (n = 8 each). Contaminants (fresh saliva and blood mixture) were applied using a micro-brush as per protocol. Composite cylinders (3 mm × 5 mm) were built and light-cured for 20 seconds. After 24 hours of storage in saline at 37 °C, specimens were tested for shear bond strength (SBS) using an Instron Universal Testing Machine at 1 mm/min. Data were analyzed by one-way ANOVA and Tukey’s post-hoc test.The 6th generation adhesive (Clearfil SE Protect) showed the highest mean SBS (24.66 ± 0.96 MPa) under control conditions, followed by the 7th generation (22.85 ± 1.01 MPa) and 8th generation (21.61 ± 1.19 MPa). Contamination before curing resulted in the greatest reduction in SBS (p < 0.001). No statistically significant difference was found when contamination occurred after curing (p = 0.22).Saliva and blood contamination significantly reduce dentin shear bond strength, especially when contamination occurs prior to adhesive curing. The two-step self-etch (6th generation) adhesive demonstrated superior performance under contamination conditions. Proper isolation remains critical in adhesive restorative procedures.