The potential applications of natural fiber composites are constrained by their varying physical (weight gained and swelling) and mechanical (tensile and flexural strength) properties across different environments, impacting the manufacturing industry involved in their production and utilization. Therefore, this article investigates the effect of various environments, such as petroleum, diesel, distilled water, and open-air exposure, on the physical and mechanical properties of the Gudro species of Domestic Abyssinia Banana (GsDAB) fiber-reinforced epoxy composite. The samples were made using the compression molding manufacturing method and subjected to these severe environments for 8 weeks. The changes in physical and mechanical properties of the composite were measured within a two-week interval and recorded. The findings indicated notable impacts on these properties of the composite when subjected to different conditions. Distilled water exposure had the most substantial effect, with the composites’ tensile and flexural strengths diminishing by 35.61% and 48.17% after 8 weeks. However, specimens exposed to diesel and petroleum demonstrated lesser reductions, with 5.44% and 4.81% of tensile strength and 8.67% and 7.5% of flexural strength, respectively, over the same duration. Similarly, the composite subjected to diesel and petroleum exhibited less change in their physical (weight and swelling) properties than those exposed to distilled water. Hence, GsDAB epoxy composites could become more prevalent applications in various industries, including gasoline stations, automotive, and residential interior construction.