Mechanical fastening is crucial in numerous industries as it permits a vast number of composite assemblies to be produced. To account for the obscure properties and concurrent inclusion of nanomaterials in various industries, the machining of nanocomposites has become a vital issue for further scrutinization. Although several pieces of literature have examined the drilling operation of polymer composite materials, very few have discerned the impact of drilling on hybrid nanocomposites and thus ascribed to a gap in the literature. Hybrid nanocomposites have different characteristics than typical polymer composites, and they perform differently when mechanically drilled. In this study, the drilling of the natural fiber (Sisal and Coir) reinforced Carbon Nanotube (CNT) based nanocomposites were investigated, and the hole quality such as roundness error, delamination factor, and taper angle was assessed. The composite was fabricated applying the hand lay-up method, and the ratio of weight fractions of the natural fibers was varied along with the drill's cutting speed, diameter, and feed rate. It was observed that the unit ratio of weight fractions of sisal and coir fibers in hybrid nanocomposite minimized the delamination factor along with surface roughness and resulted in the best hole quality, minimizing the. The findings of this study can be helpful in different manufacturing industries such as aviation and automobile industries, where drilling lightweight composite material is a significant aspect of the manufacturing process.Copyright (c) 2022 Elsevier Ltd. All rights reserved.Selection and peer-review under responsibility of the scientific committee of the Sustainable Materials and Practices for Built Environment.