The purpose of the study was to investigate the ameliorative effect of dietary rocket salad and apple cider vinegar on the oxidative stress (OS) status of broilers. Specifically, 720 Ross 308 chicks were divided into six groups: negative and positive controls (NC and PC with and without additives, Vi1 and V12 experimental groups fed with diets mixed with 5 and 10 mL of vinegar/kg, and Ro1 and Ro2 groups fed with diets mixed with 2 and 3 g of rocket salad/kg, respectively). The experimental groups Vi1 and Vi2 were fed with feed mixture moisturized with 5 and 10 mL of vinegar/kg, and Ro1 and Ro2 were fed with 2 and 3 g of rocket salad/kg, respectively. The birds’ productivity, oxidative serum parameters, and morphometric indices of the gastrointestinal tract were registered at 6 weeks of rearing. The vinegar or rocket salad additive had powerful potentials to significantly suppress (p ≤ 0.05) OS through improving the birds’ survivability, body weight gain, feed conversion ratio, and carcass yield. The highest villus height and villus height/crypt depth ratio of the duodenum were achieved by Vi2, Ro1-2, and NC (p ≤ 0.05). The villus surface area and muscular layer thickness were smallest in the PC, while they did not differ significantly in other groups (p > 0.05). Similar relationships were found in serum superoxide dismutase, glutathione peroxidase, hydroperoxide, and malondialdehyde; however, higher doses of both additives were more effective. It seems that liquid vinegar and rocket salad could have beneficial influences on the antioxidant status of birds.