This investigation explores the development and exploration of hybrid composites fabricated with flax and bagasse for enhanced mechanical performance with NaOH treatments. This process involves soaking flax and bagasse powder in water and allowing it to dry in the sun, and then washing it with a NaOH solution. To improve cohesion, these materials in varying weight fractions were mixed with epoxy resin and formed into the necessary die by hand layup. Subsequent mechanical experiments were carried out to ascertain the strengths of various composite compositions and the impact of treatment conditions. These tests included hardness, impact, flexural, and tensile testing. When compared to monolithic material, the composite material containing 25% bagasse and 75% flax treated with 5% NaOH showed the highest impact strength at 16.73 joules contributed to a rise of 25% and71% compared to monolithic material. There has also been an improvement of 31.54% in hardness and 53% in ductility compared to flax matrix material with NaOH treatment. The present investigation underscores the pivotal role that weight fractions and NaOH treatments contributed in enhancing the mechanical attributes of flax/bagasse hybrid composite materials. By using morphological analyses, this study emphasizes the significance of surface treatments in the development of superior composite materials suited to particular applications.