Nanoscale polyion complex formation via the electrostatic complexation of a polyelectrolyte and a charged drug is the most convenient method for building a drug delivery system that simultaneously realizes the carrier preparation and drug embedding. Herein, we prepared keratin/chlorhexidine complex nanoparticles (KCNPs) based on a drug-induced ionic gelation technique without using a crosslinker, organic solvent or surfactant. These KCNPs exhibited good stability even after having been long-standing for 14 days. The KCNPs were characterized using FTIR, DLS, SEM and TEM. It was found that these nanoparticles had a spherical morphology with a diameter of about 180 nm, and a negatively charged surface with a zeta potential of about −39.1 mV. The cell toxicity of the KCNPs at different dosage levels was evaluated using the MTT assay method, indicating their slight cytotoxicity at lower dosages. The antibacterial activity against E. coli and S. aureus was determined using the zone of inhibition method. It seemed that the KCNPs had better antibacterial activity against S. aureus than against E. coli. Drug delivery profiles showed that the chlorhexidine (CHX) loaded nanoparticles exhibited both pH- and glutathione-responsive character. These keratin-based complex nanoparticles can be regarded as a valuable stimuli-responsive strategy for the delivery of anticancer agents.