Benign prostatic hyperplasia (BPH) is one of the common disorders amongst the geriatric male population, affecting their quality of life. Since conventional drugs used for the treatment are sometimes accompanied by serious side effects, the search for alternative treatments remains urgent. This study aimed to evaluate the antioxidant activity and the protective effects of the aqueous and methanolic extracts of Myrianthus arboreus (M. arboreus) on a BPH model induced in male Wistar rats. The antioxidant activities of the extracts were assayed in vitro by free radical scavenging using DPPH and ABTS assays, total antioxidant capacity. For the in vivo study, rats were randomly divided into nine groups of six rats each. Groups 1 and 2 received distilled water, group 3 received finasteride (5 mg/kg), while groups 4 to 9 received 50, 100, and 200 mg/kg of M. arboreus respectively. The treatment lasted 28 days after which, animals were sacrificed. Relative organ weights, histopathological changes, total protein levels, and oxidative status were determined. In addition, some pro-inflammatory cytokines and prostate-specific antigen levels were measured. Both extracts of M. arboreus demonstrated strong radical scavenging and total antioxidant capacity in vitro. They counteracted the effects of testosterone by decreasing the relative weight and volume of the prostate, the prostate epithelium height, and the total protein level in the prostate. Likewise, they improved the oxidative status and reduced the concentrations of cytokines in the prostate, and the serum PSA level. M. arboreus extracts contain bioactive compounds with antioxidant properties which confers protective abilities against the occurrence of BPH.