<p>Biopolymeric nanocomposites have attracted considerable attention because of their biocompatibility, biodegradability, and unique physicochemical properties. It is essential to manufacture three-dimensional (3D) biocompatible micro/nanostructures using biopolymeric nanocomposites. Herein, we demonstrate the high-fidelity fabrication of biocompatible 3D features with sub-50 nm resolution using femtosecond laser direct writing (FsLDW) of a biopolymeric nanocomposite composed of egg white and sulfonated graphene (S-graphene). The biopolymer nanocomposite acts as a negative photoresist suitable for water-based lithography. The introduction of S-graphene not only dramatically lowered the laser power threshold but also significantly modulated the morphology of the 3D features constructed by FsLDW. Microstructures with porous, rough, or smooth morphologies were obtained by optimizing the S-graphene concentration and laser scanning speed. The fabricated egg-white/S-graphene microstructures exhibited biocompatibility and environmental degradability. Egg white/S-graphene was also employed to fabricate diffractive gratings with superior optical quality. This study provides a promising method to manufacture biocompatible 3D features with controllable morphology, which has potential applications in biological and photonic fields.</p>