The concept of reuse and recycle plays a very important role in using waste materials effectively. Fabrication of green composites, which adopts the reinforcement of natural and biodegradable fibres in place of synthetic fibres, is a constructive way to achieve reusability and recyclability. Hence, the sugarcane fibre, fly ash, and carbon nano tube are selected as reinforcement/filler materials for fabricating epoxy polymer matrix composite. This work is intended to investigate the flexural behaviour of the fabricated epoxy polymer composite by varying the wt. % of CNT/sugarcane fibre/fly ash. Central composite design of response surface methodology, one of the concepts of design of experiments, is used to make the experimental specimens. Further, analysis of variance is used to accomplish the influence of CNT/sugarcane fibre/fly ash on the flexural behaviour of composite. Optimized parameters are obtained to achieve the improved flexural behaviour, and the same is confirmed by the confirmation experiment. Copyright © 2021, IGI Global.