This study investigates the influence of heat stress (HS) and vitamin C (VC) and/or vitamin E (VE) on semen quality, biochemical constituents of seminal and blood plasma, antioxidant status and jejunum and ilium deoxyribonucleic acid (DNA) of roosters.  Forty-five, 32-week-old roosters were divided into five groups of nine replicates. One group was kept under a thermoneutral environment, whereas the other four were kept under HS. One of the four groups served as an unsupplemented HS group and was fed the basal diet only. The other three HS groups were supplemented with VC (200 mg/kg ascorbic acid and/or VE 150 mg/kg α-tocopherol acetate).  Vitamins fortification completely restored sperm liveability , semen pH, fertility, seminal plasma total protein and globulin to the control level. Vitamins fortification completely recovered seminal plasma and blood plasma total antioxidant capacity (TAC) and malondialdehyde (MDA), red blood cell (RBCs), haemoglobin (Hgb), packed cell volume (PCV), white blood cells (WBCs), blood plasma glucose, lipid profiles, liver enzymes, and renal function. Heterophil/lymphocyte (H/L) ratio was totally restored following VE fortification. Vitamins fortification significantly increased jejunum and ileum DNA compared with the HS group, with VC inducing a complete recovery.  In conclusion, either 200 mg /kg VC or 150 mg/kg VE improved semen quality, fertility, seminal plasma and blood biochemistry and haematology of HS roosters, with the VE group yielding greater immunity.