The present investigation pertains to the existent possibilities of the fibrous natural material Luffa Cylindrica (LC) as reinforcement to thermoset resins. The main purpose was the manufacturing of an engineering material that would, simultaneously, lead to a more sustainable world. In an effort to optimize the final mechanical properties, semi‐ green Epoxy Resin/Luffa Cylindrica (ER/LC) composites were manufactured, applying a number of different manufacturing parameters combinations. The manufacturing parameters taken into account were: (a) fiber chemical treatments; (b) the external applied pressure during curing; (c) number of plies; (d) stacking sequence effect; (e) LC's structural characteristics; and (f) the influence of fiber weight fraction on composite's behavior. The elastic flexural response of the composite polymer was found improved with respect to neat polymer's response due to fibers' nature and the applied manufacturing optimization process. This improvement was reflected to material's stiffness which optimally increased by 48% for a mechanically applied pressure of 4.6 kPa during curing. Additionally, LC fibers chemically treated with Acetone/ CH3COOH 1 wt % led to stiffness' improvement up to 30%. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41992.