ABSTRACT: The sperm recovered from the epididymal lack seminal plasma (SP), and the contribution that it makes of ions, lipids, energy substrates, proteins and other organic compounds. This research aimed evaluated the effect of SP on the oxidative status and quality of freeze-thawed epididymal bovine sperm. SP from 10 bulls was collected and pooled. Epididymal tail sperm was recovered from 16 testis-epididymal complexes. Each sample was distributed in four treatments for sperm freezing: 0% SP (control), 10% SP (SP10), 20% SP (SP20) and 30% SP (SP30). The SP’s total antioxidant capacity (TAC) was measured using the discoloration test with ABTS●+ cation radical (ABTS) and oxygen radical absorption capacity (ORAC) assays. In post-thawed semen, motility and sperm kinetics were evaluated using the Sperm Class analyzer system (SCA®) system, the functional integrity of the membrane using the hypoosmotic test (HOST), sperm vitality (SV) and abnormal morphology (AM) using eosin-nigrosin staining. Lipid peroxidation (LP), mitochondrial membrane potential (ΔΨM) and reactive oxygen species (ROS) were evaluated by spectrofluorimetry. The TAC contribution of the freezing extender was 490.2 μmol Trolox Eq/L (ABTS) and 120.5 μmol Trolox Eq/L (ORAC) for each 10% of supplemented SP. SP10 improved progressive motility (PM) but increased AM. SP20 had a higher PM, average path velocity (VAP) and linear velocity (VSL) but reduced SV. SP30 increased VSL but scored lower in the HOST than SP10 (P < 0.05). All SP treatments increased ROS and LP. In conclusion, the addition of SP contributed to the antioxidant capacity of the freezing extender and can improve the motility and kinetics of bovine epididymal spermatozoa. However, it can increase oxidative stress and alter sperm morphology and membrane integrity.